Merge branch 'hotfix/0.8.11'
Add missing gettext text domain to the "Clear Search" button.
Fix RTE saving on the Settings admin page.
Properly search the child template path for custom template files.
Update Google+ icons.

closes gh-359
Add Tumblr to social media options.

closes gh-360
Add Goodreads to social media options.

closes gh-361
Add IMDb to social media options.

closes gh-362
Update gitingore so as to not exclude the icon folder.
Add icon files for new social media options, Goodreads and IMDb.
Update changelog.txt.
Update readme.txt.
Bump version to 0.8.12.
Add missing upgrade notice to readme.txt.
Merge branch 'hotfix/0.8.12' into develop