Enhance Grant batch update

NB: Please leave this as 4.5 - The JIRA system is being used for managing extensions related to Grant in anticipation of it becoming an extension.
Note: this is just an extension at this point and so 4.5 core release is not dependent on its completion.

1. Rename the Update Grants action on grant search results to Batch Update Grants via Profile.
2. Implement a UI similar to Batch Updates via Profile for Contacts, with core and custom fields for Grants and Contacts allowable in the profile, including all field types specifically including contact references.
3. This is to be done as an independent extension to be released with CiviCRM 4.5, since CiviGrant will not be moved into an extension until 4.6.
4. Tadpole will be responsible for QA.
5. Funding is provided by the McKenzie River Gathering Foundation.
6. Testing with live MRG data to be coordinated with Korlon.