Update translation pt_BR
New version of _dt_style_cleanup_multi_instance.

This fixes 2 issues:

- first some SQLite distributions are not compiled to support ORDER BY LIMIT
  on an UPDATE statement.

- second, the previous version were not properly working when there was
  multiple time the same multi_instance value for a style.

This new version is moving away from an SQL only implementation but will
be in turn easier to understand and maintain. We could revisit this
implementation if SQLite start supporting ROW_NUMBER.
Some fixes to WebP related build scripts

We were able to compile darktable when WebP wasn't found just because of
a bug in the WebP detection code.
Merge pull request #378 from edgomez/bugfix

tonecurve: display usual guides whatever histogram mode is chosen
Some more cmake cleanup
Merge pull request #379 from guitorri/up_pt_BR

Update translation pt_BR
Merge branch 'cleanup-multi-instance'

* cleanup-multi-instance:
  New version of _dt_style_cleanup_multi_instance.
colorspaces: adobergb gamma is technically not quite 2.2

from: https://github.com/hughsie/colord/commit/7efe9fe132dac72adf06c5a36112b8028d0499b4

According to http://www.adobe.com/digitalimag/pdfs/AdobeRGB1998.pdf they are
*not* 2.2, but '2 + 51/256' which isn't quite 2.2.

This is also the value used by ArgyllCMS, many thanks to Elle Stone for the hint.

Important practical note is that in both cases (2.2 and 2.19921875) results in a profile
encoded with gamma 2.199219 which is probably due to limited accuracy in the ICC spec.
Fix possible buffer overflow
Updated Czech translation
Merge pull request #380 from milankni/translation-cz

Updated Czech translation
mention lua in the release notes
Go through git log and update the RELEASE_NOTES
* doc/AUTHORS: add punctuation to the list of contributors so it can be
  included cleanly in the manpages with the rest of the authors.
* doc/darktable.pod: updated.
* doc/darktable-cli.pod: new.
* doc/CMakeLists.txt: updated to handle darktable-cli as well.
Remove 'pl' from doc/usermanual/po/LINGUAS, as there is no corresponding pl.po
Merge pull request #383 from levitte/usermanual-fixes

Remove 'pl' from doc/usermanual/po/LINGUAS,...
lua : rework the way types representing an object with an int id work

this fix bug #9698 where equality wouldn't be true in all case
Have the usermanual in PDF format end up in the build directory, not
the source directory, just like all other formats.
Merge pull request #384 from levitte/usermanual-pdf-in-build-directory

Have the usermanual in PDF format end up in the build directory
remove freetype cmake module - it's not needed and doesn't work with 2.5.1 release