No direct path to Time Signatures, Key Signatures, or Symbols on master palette (regression)

Ubuntu Studio 14.04, GIT commit: 12e848f

Formerly (in 1.3), you could press "K" to go to the key signature dialog, "T" for time signature, "Z" for symbols. These are all on master palette now, and there is no more direct shortcut to reach those tabs. Simple solution: define new actions that invoke showMasterPalette with appropriate strings as arguments (which causes it to start up on the specified tab). Since "K" is used in tablature, maybe we switch to Shift+K and Shift+T as default shortcuts for key and time signature.