Rename wagtailadmin_nav tag library to wagtailadmin_tags in preparation for moving other miscellaneous wagtailadmin tags there
move ellipsistrim filter to wagtailadmin_tags
move fieldtype filter to wagtailadmin_tags
Move meta_description filter to wagtailadmin_tags
Move page_permissions template tag to wagtailadmin_tags
Add hooks to insert custom CSS/JS into the editor interface
Set a richtext-image class on images within rich text areas, and set styles on that class so that they get aligned appropriately in the editor interface. Previously the styles referred to bodytext-image, which was specific to RCA's custom image formats
Remove RCA-specific style for H2 elements (and replace the now-complete TODO with a mini-rant about semantic markup)
Also remove RCA-specific top padding from H2 elements
Merge pull request #182 from gasman/feature/editor_css_hook

Add hook for inserting site-specific CSS/JS into the editor interface