Add back 'refresh' and 'settings' to folder context menu.

Both items are commonly used even by the average user (and likely both
are used more commonly than 'clear local messages'), so it makes
sense to provide them in the context menu as well as the action bar.
IntelliJ IDEA: Update android support version per e7964682564e7ea6049c6dee6b4e7f0a569564dc.
Add Maven pom for ckChangeLog.

Out IntelliJ IDEA project is using Maven for dependency management.
IntelliJ IDEA: Project updates to drag in ckChangeLog.
IntelliJ IDEA: Remove unnecessary "library" entry.
Add back account settings to account context menu.
Merge pull request #224 from maniac103/extend-folder-menu

Add Refresh' and Settings to folder context menu.

Also add Account Settings to the account context menu.
Bumped manifest to 4.320
Use separate table to store the thread structure
Avoid full table scan when creating the threaded message list
Optimize setting flags for whole threads
Fix getFoldersAndUids() for threads
Rewrite/optimize some SQL statements
Fix copy/move when not in 'single folder mode'
Close thread view when last message has been moved/deleted
Merge branch 'threading_schema_change'
Add ckChangeLog to about dialog
Update changelog
Add button to show changelog to 'About' dialog