Typo button2 -> button3.
Allow esc to close alerts.
Show validity with a color indicator.
Revert "Easier way to set the subject."

Don't work on older systems.
This reverts commit 9aec4a299cab581af3fc2b3e4e00644d12408e57.
Merge branch 'dev' of github.com:GPGTools/GPGKeychainAccess into dev