bitbake.conf: Define USRBINPATH globally instead of individually
Many recipes are now having to define PERLPATH and PYTHONPATH variables.
Creating USRBINPATH in bitbake.conf means we can remove all these lines
from the many recipes now needing this and simplify the code changes
needed in each case, reducing the chance of errors being introduced.
Also fixup glib python binary location issue and fix function indentation.
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
