Move most libraries to Gallery (rename-only commit to be careful with revision histories).

--HG--
rename : modules/gallery/libraries/Block.php => modules/gallery/classes/Gallery/Block.php
rename : modules/gallery/libraries/Breadcrumb.php => modules/gallery/classes/Gallery/Breadcrumb.php
rename : modules/gallery/libraries/IdentityProvider.php => modules/gallery/classes/Gallery/IdentityProvider.php
rename : modules/gallery/libraries/drivers/IdentityProvider.php => modules/gallery/classes/Gallery/IdentityProvider/Driver.php
rename : modules/gallery/libraries/InPlaceEdit.php => modules/gallery/classes/Gallery/InPlaceEdit.php
rename : modules/gallery/libraries/Menu.php => modules/gallery/classes/Gallery/Menu.php
rename : modules/gallery/libraries/SafeString.php => modules/gallery/classes/Gallery/SafeString.php
rename : modules/gallery/libraries/Sendmail.php => modules/gallery/classes/Gallery/Sendmail.php
rename : modules/gallery/libraries/Task_Definition.php => modules/gallery/classes/Gallery/TaskDefinition.php
rename : modules/gallery/libraries/Gallery_View.php => modules/gallery/classes/Gallery/View.php
rename : modules/gallery/libraries/Admin_View.php => modules/gallery/classes/Gallery/View/Admin.php
rename : modules/gallery/libraries/Theme_View.php => modules/gallery/classes/Gallery/View/Theme.php
Typo - fix case of Gallery.php filename.

--HG--
rename : modules/gallery/classes/gallery.php => modules/gallery/classes/Gallery.php
Fix class declarations for just-moved libraries (except Menu - it needs extra work).
Break up the Menu library into its five classes, each with its own file.
Add class extensions for just-moved libraries.
Merge pull request #224 from shadlaws/gallery_some_libraries_task

Move/rename/extend for most gallery libraries.
Follow-on typo fix for gallery.php -> Gallery.php.