Use a separate impersoanted thread for filesystem access on Windows

[chevah-robot]

T2847 task was created by adiroiban on 2015-05-13 06:56:13Z.
Last changed on 2015-07-01 11:42:43Z.
PR at https://github.com/chevah/server/pull/725.

so that the main tread is not affected by filesystem operations

[chevah-robot]

Comment by pqm at 2015-07-01 10:30:57Z.

adi requested the review of this ticket.

needs-review

[chevah-robot]

Comment by adiroiban at 2015-07-01 11:42:43Z.

bad id