Support Apple OSX Executable Signing

[fpietrosanti]

This Ticket for the implementation of support in APAF, to document and facilitate the signing of resulting PE executable with a X509v3 digital certificate following apple code signing guidelines https://developer.apple.com/library/mac/documentation/Security/Conceptual/CodeSigningGuide/Introduction/Introduction.html .

The Signing verification must work on:

• Mac OS X 10.6
• Mac OS X 10.7
• Mac OS X 10.8

cc @hellais @mmaker @mogui

[fpietrosanti]

Various information about Py2app uses and code-signing:

• http://mail.python.org/pipermail/pythonmac-sig/2011-November/023404.html
• http://shreerangsblog.blogspot.it/2012/08/code-signing-on-mac-without-xcode.html
• http://permalink.gmane.org/gmane.comp.python.pyobjc.devel/4611

[fpietrosanti]

As noted by Rigel, this ticket may conflict with #21 and it may require some serious hacking to avoid the issues of timestamp variation applied by signing process.

[fpietrosanti]

Not even pyinstaller support signing http://groups.google.com/group/pyinstaller/browse_thread/thread/469e9451227b74fe