change --picky-developer into --non-picky-developer

[Stefan (metze) Metzmacher]

Hi,

I've created a patchset that does fix a lot of compiler warnings
and lets --enable-developer imply -Werror by default.

This uses a allow_warnings argument to SAMBA_SUBSYSTEM/LIBRARY/MODULE,
which is False by default. Which means autobuild will protect us
from having new warnings introduced.

If a developer has a compiler that generates more warnings
(as the gcc from ubuntu 10.04 or 12.04) he needs
--non-picky-developer in order to avoid -Werror.

Overtime we can aim to add more -W* flags and
reduce the number of allow_warnings=True usages.

Please review and push
https://git.samba.org/?p=metze/samba/wip.git;a=shortlog;h=refs/heads/master4-picky

Thanks!
metze