Vagrant windows 1.3

New features:
- Better reload/reboot support. Shared folders are re-initialized before provisioners are run so they don't error out after a reload/reboot. Provisioners don't run if a reboot is in progress or imminently scheduled.
- Powershell exit codes are properly returned rather than just being True or False.
- Don't error out a VMware provider if the box has a secondary NIC, just display a warning.
- Abstracted the Vagrant machine object to aid in unit testing - added additional unit tests.

Fixed issues:
- 131
- 130
- 129
- 128
- 127
- 126
- 125
- 119
- 74