Added new setting to sort forums by unread posts as per SALR functionality.

This involves:
New preference
Renaming existing preference newThreadsFirst to newThreadsFirstUCP (This will lose users existing preference unfortunately)
New column on the threads table marking if a thread has been looked at
Updated Forum Display Fragment to show #posts/0/blank where required
Adding upgradePreferences method to upgrade preferences when a new version installs.
Merge pull request #185 from Bonnett/sortthreads

Added new setting to sort forums by unread posts as per SALR functionality
Fixing issue where forum list isn't parsed properly
Merge pull request #191 from Bonnett/master

Forum list isn't parsed properly
Fixing issue where "Show Inline Images" did nothing on images
Typo Fixing
Merge pull request #192 from Bonnett/master

Fixing issue where "Show Inline Images" did nothing on images
Unread post fixes
 - new threads now go to the first page rather than the last
 - Marking a thread as unread updates HAS_VIEWED_THREAD
Fixing issue where viewed threads keep going to the first page instead of next unread
Fixing bookmark detection
Now parsing multiple bookmark types, however the toggle bookmark option is currently just an on/off setting rather than allowing categories to be chosen
Merge pull request #193 from Bonnett/master

Fixes due to new "sort forum by unread posts"
Merge pull request #194 from Bonnett/bookmarks

Fixing bookmark detection
Hide IDEA workspace files.