[FIX] Sparkle ignores updateSource.
[FIX] Mail preferences sometimes too slim.
Show correct build number in preferences.
Merge branch 'master' into dev
[FIX] Default security method is now automatically set, based on the availability of keys.

[#584 state: fixed]
[FIX] Default security method is now automatically set for replies, based on the availability of keys.

[#584 state:fixed]
cleanOldPlist added.
gpgc.verbose removed.
Convert \n to \r\n
Parentheses added.
objectAtIndex instead of []
Use dataByConvertingLineEndingsFromUnixToNetwork
[FIX] ::gpgmail-start-pgp-part:: sometimes not replaced.

::gpgmail-start-pgp-part:: is showed sometimes if a message contains a
non clear-signed part.
Warnings removed.
High resolution images.
Simpler image name mapping.
certificate.png added.

TODO: Replace encryption.png by the correct image.
[582 state:fixed] Copy version by clicking on it.
A bit more space for the version label.
Fewer lines for properties.