Optimize string comparisons

Use their hashes, if initialized, to short-circuit the "not-eq" path.

Should speed up comparisons of interned strings.

fix typo in Compiler/Options.py

Reported-by: Paulo Andrade <paulo.cesar.pereira.de.andrade@gmail.com>
References: https://bugzilla.redhat.com/show_bug.cgi?id=1406533Signed-off-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>

A few more wrappers in libcpp.algorithm and libcpp.vector

Fix cythonize(source_filename, cache=True) under Python 3

This fixes #1540.

This fully resolves #1542.

Fixes #1541

Fixes GH issue #1538.

errno.h on FreeBSD contains ENOATTR instead of ENODATA