address user comments
run_tests_if_main() can also run with nose, and is smarter
glir: WIP on ripping gloo in two. Buffer implemented.

Buffer class is implemente via glir. Still need to simplify the
buffer class by removing local storage.
gloo: remove local storage from buffer
style and py2 syntax
gloo: address reviewer comments
glir: simple fix
glir: gloo buffer tests pass again
gloo: fix setting of _nbytes and _size, plus minor fixes
glir: restore GLObject.target for now
Fixing some issues; hopefully tests can pass again