Update "arm9tdmi vector_catch" command description to highlight both
use cases (display configuration, or first change that config) and
to explain a bit more about what this is:  an alternative to using
hardware breakpoint resources.

Note that I tried this on an arm920t, but it didn't work.  Set bits,
then examined them and they weren't set.  And it didn't seem to act
as if vector triggering was noticed, either.

Also some minor unrelated tweaks:  @ignore some unused or don't-use
event names; fix a few typos; tweak chip-specific reset descriptions.


git-svn-id: svn://svn.berlios.de/openocd/trunk@2203 b42882b7-edfa-0310-969c-e2dbd0fdcd60