Smarter way of handling settings

Removed monkeypatching from cms.__init__
Removed cms.conf.*
Added cms.utils.conf.get_setting(name)
Refactored all (CMS) setting accesses throughout the code base

This should fix issues with more recent gunicorn version (>0.12) as
well as make the code less hacky.

Known issues on this branch:

* ApphooksPageLanguageUrlTestCase.test_page_language_url_for_apphook
  currently fails, not sure why.
* SettingsTests.test_cms_templates_length,
  SettingsTests.test_cms_templates_none and
  SettingsTests.test_cms_templates_valid all fail currently because
  cms.conf.patch.post_patch and cms.conf.patch.post_patch_check are
  no longer available.
delete orphaned plugins command and tests
delete orphaned plugins command and tests
docs for delete orphaned plugins command
Stop loading the adminmedia template library
copy_relations() docs expanded
only call plugin_report() once
more explanations of copy_relations()
Merge pull request #1569 from rizumu/adminmedia

Stop loading the adminmedia template library
Merge pull request #1570 from evildmp/copy_related

copy_relations() docs expanded
Update cms/utils/page_resolver.py

see issue #1573
Merge pull request #1575 from barsch/patch-1

get_page_queryset_from_path() in cms/utils/page_resolver.py not 100% site aware
removed two redundant icons; use Django's instead
Troubleshooting section for custom plugins
doc change - more precise wording
add unselectable IE attribute to wymiframe to prevent IE from losing
cursor focus when inserting plugin object (thus throwing escaped HTML to
the top of the area).

Tested in FF18, Chrome 23, Safari 5.1.7 (win), IE8, IE9, IE10.
test for no placeholder
Merge pull request #1580 from benjaoming/develop

Troubleshooting section for custom plugins
Merge pull request #1583 from evildmp/fix-empty-placeholder-error

test for no placeholder
Merge pull request #1582 from at3560k/develop

Add unselectable IE attribute to wymiframe to prevent IE from losing focus