#44 locking in mod_file and mod_raw

[Mark Lentczner]

Both mod_file and mod_raw have a NameSpace::Lock object in
their request objects. This to ensure that they are properly sync'd
against requests to mod_render.

However, both hold the lock for the entire request. They should
give it up once the output has been determined, but before it is
streamed back to the requester.

For mod_file this could be difficult, as the output is streamed
directly from the object system - so in theory we need at least a
read lock the entire time.