- calculate cycles since last executed instruction when cycle-accurate tracing is enabled

- increase memory pseudo-image cache size to 1024 byte for improved trace analysis performance
- added OpenOCD+trace as an ETM capture driver example implementation
- new usbprog driver (thanks to Benedikt Sauter)


git-svn-id: svn://svn.berlios.de/openocd/trunk@186 b42882b7-edfa-0310-969c-e2dbd0fdcd60