Only enable debug logging when running a debuggable build

There have been some complaints from Android developers that get flooded
by K-9's log messages when debugging their own apps. Oops :)
Remove submenu from the account context menu

There seems to be a bug in Android that makes submenus inaccessible on
some devices, e.g. the Samsung Galaxy S2.
https://code.google.com/p/android/issues/detail?id=53239
Update catalan translation.
Escape apostrophe.
Don't use extended notifications when privacy mode is enabled
Explicitly export content providers

With SDK 17 the default value for 'exported' changed to "false".
Remove contacts helper code specific to SDK 7
adapt broken pop3 server
Add initial Gradle support
Add support for building and running our tests with Gradle
Don't crash when MessageList is started with no intent extras
adapt to a corner case for broken server.
Update Russian
a much more robust tools/build-beta
Update changlog with changes for 4.390
Update changelog
changelog for 4.392
update changelog
Updated Japanese translation of the changelog on stable branch
Updated Japanese translation of the changelog.