[ADD] google_meeting module v.7.0

This PR contains the module 'google_meeting' which provides a solution for synchronizing crm_meeting in Odoo v7.0 with Google Calendar.

I applied on the module https://github.com/solutions2use/google_api  developed by @solutions2use  a strong PEP8 cleanup and a bit of refactoring. I also renamed the module to google_meeting because it seemed more suitable.

See the description in the __openerp__. py for the installation notes.