test kprobes feature
fix register naming rule to conform ARM manual
remove kprobes test function outside kernel tree
add build-time option: CONFIG_KPROBES
replace fpb-related symbols with hw_breakpoint
revise description of kprobe-arch.c
revise kprobe description in init.c
trivial fix: remove trailing space
trivial fix: conform to width 80
rename hw_breakpoint.[ch] to hw_debug.[ch]
rename hw_breakpoint_init to hw_debug_init
add DWT Watchpoint
remove kprobe code from hard_fault_handler