Instrument multiple functions and count calls of user given "enter"
and "exit" functions.

> igprof -fmint FUNCTION1:LIBRARY1,FUNCTION2:LIBRARY2... (instruments
	functions that pass return value in %rax register. Max 10 functions)
> igprof --fmregexp LIBRARY1:LIBRARY2:LIBRARY3... REGEXP (instruments
	functions that can be found in given libraries and match to REGEXP.
	Function need to return value in %rax register (Max 10 functions)
> igprof -fmdouble FUNCTION1:LIBRARY1,FUNCTION2:LIBRARY2...(instruments
	functions that return value %XMM0 register.
All the functions increment the same counter.

> igprof --fenter-exit ENTERFUNCTION:LIBRARY EXITFUNCTION:LIBRARY

Counts calls to given functions. User can specify up to 10 enter functions and
	10 exit functions. Functions should return value in %rax register
Enter functions share one call counter and exit functions share another counter.

The x86 instruction length decoder has a new design. More supported instructions
added and the length lookup is now done trough opcode map tables.