File mtime and ctime should be restored on check-out

[GoogleCodeExporter]

It seems that currently, the "last changed" dates etc. are not stored and 
therefore not propagated to clients... This kind of messed up my pictures 
library for all files that did not have the "date taken" metadata set within 
the file - which was true for a lot of old pictures and basically all videos 
:-/.

I think that this file information should be transferred to all clients. First 
one to commit a file should also commit file metadata, others to check out that 
file should have the metadata set to the respective values.

Original issue reported on code.google.com by [email protected] on 12 Dec 2012 at 11:22