Support CMS-like view on files for users

[jamoore]

Adding to the OmeroFs use cases here: a user would most likely want a filesystem-like view on his or her scripts and script outputs. First to find the scripts, there should be a directory which can be well organized:

  scripts/
   |_ matlab/
   | |_ a.m
   | \_ b.m
   |_ python/
     |_ a/
     \_ b/

(This is not only important for organizational purposes, but the naming of say the matlab scripts is criticial to being able to load them from the path.)

Then, all job outputs could go in another directory:

 jobs/
 |_ 001
 | |_stdout
 | \_stderr
 |_ 002
   \_...
 \_ 003
   \_...

One question is how do we present these directory structures to the user? Making them show up for the server is fairly straight-forward, but you can imagine a user wanting to make a listing of all files:

 AllFiles/
 |_ OmeroFs1
 |  |_ scripts/
 |  \_ joboutput/
 |_ OmeroFs2
    \_ somethingelse

but then what do you do about permissions?

Note: A possible alternative to having all of this done in OmeroFs would be to use tagging (one tag for each directory level), but I don't think this would make the stored files nearly as easy to use.

[cblackburn]

Moved to Future to clear from 4.0. Needs to be rescheduled.

[cxallan]

Closing in favor of the overarching story #909.