Add fdbsql.rest.resource configuration item with list of enabled rest
resources to configuration. Plus RestServiceImpl using the list to
enable (or not enable) resource. Removed model and direct resource from
the list. 

Update the RestServiceFilesIT and RestServiceScriptsIT to turn back on
the Rest resources they test.
merge tjoneslo: Add fdbsql.rest.resource configuration item

Merge pull request #908 from tjoneslo/akiban-server/remove-direct-entity
https://github.com/FoundationDB/sql-layer/pull/908