[REF] simplified init_db/load_modules:

[REF] simplified init_db/load_modules:
- removed unnecessary call to openerp.modules.db.initialize() in openerp/service/web_services.py
  as the pooler.restart_pool() call just next after is already doing it.
- made the try/finally section bigger in openerp/modules/loading.py, to inlcude
  the first cr.execute.
- abstracted the test to check if a database is initialized.
- removed unnecessary "if cr:" as the cr is nevertheless used after that.

bzr revid: vmt@openerp.com-20110517091822-pjtw6sc1s5assbr5