Minor documentation update.
Merge pull request #6 from BTAS/master

sync with BTAS/BTAS after Toru's fixes for compiling BAGEL
replaced .begin and .end() with std::begin and std::end in many places.
Merge branch 'master' of https://github.com/evaleev/BTAS

Conflicts:
	btas/generic/axpy_impl.h
Merge pull request #23 from evaleev/master

Switched to std::begin and end in most places