Remove dynamic scoping with File from class nova.

Resource defaults are applied to all file resources
in class nova using File. In some circumstances the
scope of these defaults becomes too wide, causing
a dependency cycle. This commit removes the dynamic
scoping and instead explicitly defines the parameters
of each file resource to avoid creating dependency
cycles. Functionality should otherwise be identical.

Change-Id: I41d85e65ea73c54ce1a8be292ef3f781e17e48a7
Closes-Bug: 1349765
Merge "Remove dynamic scoping with File from class nova."