move benchmarking code into rhash utility
Interrupting benchmark by Ctrl-C
remove duplicate code from the library test
report clocks per byte in benchmark
rewrited comments and moved code
refactoring usage of file stat

Conflicts:
	common_func.c
removed usage of old file stat code
removed old stat code
bindings: return NULL in case of error in php module
bindings: corrected error handling in php module
changed --printf format names of sha* hash functions
a value [on|yes|true] sets a boolean config variable to true