Pcbnew: fix 45 degree rotation angle undo and global variable elimination.
Merge changes from testing head.
Pcbnew: change general properties dialog rotation angle to text edit control.
Pcbnew: rotate footprint hot key fixes (fixes lp:1066182).

* Change general properties dialog to allow for entry of arbitrary rotation
  angles for greater than 0 to 90.
* Move global rotation angle variable into PCB_EDIT_FRAME object where it is
  used and add accessors.
* Change rotate footprint undo operation from UR_ROTATE_XXXX to UR_CHANGE.
* Create function to remove trailing zeros from floating point wxString
  objects.