- fixed target->type->poll() return value

- fixed target->type->poll() return value
- added arch_state to show status of currently selected target
- simplified target->type->arch_state() api.
- clean up telnet output a bit
- fixed GDB output for arch_state
- removed a couple of unecessary exit()'s
- cleaned up error propagation a bit in a few places

git-svn-id: svn://svn.berlios.de/openocd/trunk@332 b42882b7-edfa-0310-969c-e2dbd0fdcd60