lean up some loose ends with the ARM disassembler

 - Add a header comment describing its current state and uses
   and referencing the now-generally-available V7 arch spec

 - Support some mode switch instructions:
    * Thumb to Jazelle (BXJ)
    * Thumb to ThumbEE (ENTERX)
    * ThumbEE to Thumb (LEAVEX)

 - Improve that recent warning fix (and associated whitespace goof)

 - Declare the rest of the internal code and data "static".  A
   compiler may use this, and it helps clarify the scope of these
   routines (e.g. what changes to them could affect).


git-svn-id: svn://svn.berlios.de/openocd/trunk@2675 b42882b7-edfa-0310-969c-e2dbd0fdcd60