Minor behavior fixes for the two JTAG reset events (C/internal,

Minor behavior fixes for the two JTAG reset events (C/internal,
and Tcl/external):

 - Reorder so *both* paths (TCK/TMS or TRST) can enable TAPs with
   ICEpick ... first C code flags TAPs that got disabled, then call
   any Tcl code that might want to re-enable them.

 - Always call the C/internal handlers when JTAG operations can be
   issued; previously that wasn't done when TRST was used.

Plus some small cleanups (whitespace, strings, better messaging
during debug and on some errors) to reset-related code.

git-svn-id: svn://svn.berlios.de/openocd/trunk@2730 b42882b7-edfa-0310-969c-e2dbd0fdcd60