support for complex in power ufunc
Merge remote-tracking branch 'origin/master' into npymath-complex
complex pow fix
Merge remote-tracking branch 'origin/master' into npymath-complex

Conflicts:
	numba/targets/ufunc_db.py
fixed cpow case for cpow(0.0, 0.0)
fix power for non-complex
codegen autoregister for ufuncs in ufunc_db
removed spurious print
support for complex in sign ufunc

also added support for complex comparison in npyfuncs that are needed
to implement sign.
ufunc abs complex support
complex support for ufunc rint
added conjugate(conj) ufunc to npm, including complex support
fixed conjugate_npm test, as it was clearly wrong
updated documentation on numpy_support.
complex support for exp ufunc
complex support for ufunc exp2
support complex in log ufunc
complex support in ufunc log2
complex support for log10 ufunc
ufunc expm1 complex support