mod_base: filter_date now also accepts date / datetime lists as input

Documented it as well, whoohoo.
mod_bootstrap: Correct the path to the icons
mod_comment: Default form style to vertical

The horizontal form is not so nice with forms with few or a single
input field, it disturbs the horizontal rhythm.

Added form_class block so the style can be overridden.
mod_survey: Add empty option in narrative dropdown question when required

This way, the first option value is not selected and people are forced
to make a choice when the question is required instead of defaulting
to the first dropdown option.
mod_survey: Update translations
mod_base: Fix preview thumbnail notification return format
core: remove warning in z_search
mod_oembed: Default embed max width to 640
core: Make blog skel site nicer

Miscelaneous small tweaks to make the default site look nicer.

Fixes #415
mod_survey: In narrative-type questions with select, show labels instead of indices
mod_acl_simple_roles: Remove reference to institution category

Institution is not part of the default domain model.

Fixes #184
mod_admin: media connect dialog had multiple selected pills

When using the embed image from TinyMCE button.
mod_base: Fix embedding of images in TinyMCE

Somebody should verify if this fix is correct for the other cases that
I cannot reproduce.

Issue #309
blog skel: Remove background image

As we're now using bootstrap, the navbar is rendered using a gradient.
translation: Update polish translation

Thanks, Piotr Meyer! :)
Fixes #479

Squashed commit of the following:

commit c567ab76bedd4cf9f967abc5cfaa7fec5930b6b6
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Wed Dec 12 21:54:25 2012 +0100

    mod_seo_google translation (warning: incomplete pot file!)

commit ff7b60f520a2e96ec3b5aee99801ead68109be71
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Wed Dec 12 21:49:34 2012 +0100

    Bringing some consistency into mod_admin PL translation.

commit e7c405aa8a8a114aa202842e365e5857ad83737e
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Wed Dec 12 21:47:15 2012 +0100

    mod_import_csv final PL

commit f27392c27cf238f3d4a6e808d9365426960ff880
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Wed Dec 12 21:40:52 2012 +0100

    mod_backup final PL

commit 1e20ea37f2c129abc880d1c02ec9625ea133dc30
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Wed Dec 12 17:07:21 2012 +0100

    Typo.

commit 0b95a5a9e91bc2a7e69ccb691c1f9c922847b8a3
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Wed Dec 12 16:53:02 2012 +0100

    mod_survey partial PL translation

commit 3c0a491cea3ee9af82ffe987e2a24f7cc099d41e
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Wed Dec 12 16:30:29 2012 +0100

    Corrected incostintency ("Logi" and "Dziennik poczty").

commit 8674695eb095525981e2bf0041ae3a828a24ce38
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Wed Dec 12 16:27:13 2012 +0100

    mod_mailinglist - updated PL translation.

commit 0be223211cdda35ec8e640c985333c98dcb51946
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Wed Dec 12 16:19:35 2012 +0100

    mod_facebook final PL

commit 3123caf086f868fdd31b9708907ba32742766938
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Wed Dec 12 16:17:05 2012 +0100

    mod_development final PL

commit 191642df03c095530f27152f098142fd065e8b1d
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Wed Dec 12 15:52:22 2012 +0100

    mod_authentication final PL

commit adb71fbf39b76c338b73f2da7ece856def46cf3e
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Wed Dec 12 15:48:22 2012 +0100

    mod_admin_modules final PL

commit e787c06dc29da2a9c0f53b76c1869d8d4be0b449
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Wed Dec 12 15:47:23 2012 +0100

    mod_admin_identity final PL

commit 00e7b8edc3660f7b97e11fa638baac3c861860ad
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Wed Dec 12 15:45:34 2012 +0100

    mod_admin_config final PL

commit 513d139ccc6137a082c5e37761ea76cfd5c5b364
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Wed Dec 12 15:43:48 2012 +0100

    mod_admin_category final PL

commit 6bc1aa48739b057b2e0726babae233d470ef7cf3
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Wed Dec 12 15:41:55 2012 +0100

    mod_admin final PL

commit ad06f412972e2deba29a0427b4aef58f0a7b4868
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Wed Dec 12 15:38:33 2012 +0100

    mod_acl_simple_roles final PL

commit 193ba33f73f5f88eacab680a57680bde99fcc188
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Mon Dec 10 20:41:37 2012 +0100

    Small change.

commit 8cbcb36353b72330f3c828f15d012a1d35a587fd
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sun Dec 9 23:26:44 2012 +0100

    mod_geomap PL translation

commit 957ed32508d6e1a13f3e738950b5464736f3dc7d
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sun Dec 9 23:08:52 2012 +0100

    mod_import_csv PL translation

commit f365bd00fc3a6efb17eed872a03cba3385723a2a
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sun Dec 9 23:02:28 2012 +0100

    mod_logging PL translation - corrections

commit ff746ea0a78a83b92721f1d9e1d4835697ba3934
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sun Dec 9 22:58:41 2012 +0100

    mod_oauth PL translation corrections.

commit 9bb2e0598d9f7765fa93a810c2b3a3103d3ab6f7
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sun Dec 9 22:53:48 2012 +0100

    Small corrections to mod_oembed

commit 3dea9b5f84cb443c1aca5e049fb6c6dd7ba5a80e
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sun Dec 9 22:40:20 2012 +0100

    Small correction - path to translation module.

commit ae3bf9f84f687d5db75dda3cd405d5ea78f1d063
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sun Dec 9 22:37:48 2012 +0100

    Initial mod_twitter PL translation.

commit a3b9b9f7a3c5baef14c34328e0d3e9d46327ca3d
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sun Dec 9 22:28:05 2012 +0100

    mod_video_embed initial PL translation

commit 53b51df5324a9a62c79bfa18a51c13d186a880e3
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sun Dec 9 15:10:57 2012 +0100

    Small style corretion.

commit 41e52dd1f0ba989ffe236705d67d4b7ddb64d069
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sun Dec 9 15:09:14 2012 +0100

    Small fixes

commit 866e175b6f453ec6dab6a2b602a042115614da78
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sun Dec 9 15:03:46 2012 +0100

    mod_admin corrections and additional translations (PL)

commit 557456299579a72a0471ed86e8d4064bdd5e2f72
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sun Dec 9 14:28:23 2012 +0100

    Initial version of mod_base_site PL translation. Not tested yet,
    date format should be corrected.

commit c950bb695c0bed135086e32cded4821cafe76d98
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sun Dec 9 13:28:50 2012 +0100

    mod_admin_predicate PL (note: someone with better background should
    review this)

commit 2f0bfcaca0ee99ebaa936de714476e5654fe8655
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sun Dec 9 12:52:36 2012 +0100

    mod_comment translation (PL)

commit b53f4167368362371b7b621ef84401778550dfe8
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sun Dec 9 12:19:27 2012 +0100

    mod_menu PL translation

commit e8203bdcbad7e97a11c067b2ba4d295d26f25135
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sun Dec 9 12:12:13 2012 +0100

    SEO is SEO in PL

commit e0ef4c456d9c1fbf93c8892f5f993481fe6caf71
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sat Dec 8 22:47:29 2012 +0100

    Partial translation (PL).

commit 4fa5a37a6b06117da98b4ed6c251a154fbccd454
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sat Dec 8 20:58:49 2012 +0100

    Second batch of fixes and translations in pl.po files.

commit 14eeca1273ddbc0227ae6be788e633ff13727f02
Author: Piotr Meyer <aniou@smutek.pl>
Date:   Sat Dec 8 13:17:29 2012 +0100

    First part of mod_base translation (PL, not finished yet)
mod_base: Make the return value of /api/base/upload into proper JSON on success

.. and document that, of course.
deps/ua_classifier: Update submodule

.. to include newer openddr.dtree UA classifier file.

Fixes #470
Added a 'Share page' dialog, replaces separate buttons in page meta bar.
mod_survey: delete en.po, which is not needed.
mod_survey: show alert when form doesn't validate.
Issue #371