Modified ring+sector matching stuff.

Now there are two options:
    1. Ignore ring+sector matching entirely (set SIGMA of the window to zero).
If you do this you just get the ring assuming that you set TAKE_E_RING in the config file.
    2. Do the ring+sector matching as before (set SIGMA to some non-zero value).
If you do this, the code attempts to find a match just as before. However, if
it doesn't find one, it sets the sector to the fake "sector 9" and takes
phi at the center of the wedge. One can gate on matched vs. non matched events
in the resulting ROOT file simply by looking at sector number (sectors 1-8 mean
a match was found, sector 9 means it wasn't).

NB - changes are still untested; Eames will need to do this.