restructuring of the data reduction routines... giving a single framework
for the different telescopes:

Note: so far this has only been tested on ARO data.
Lofar data is close, but needs testing. Next commit will address this

** scintellometry/trials/vlbi_b1919/reduce_data.py
 the new driver, controlling which telescope/object/dataset to reduce
 and what to do (dedisperse, fold, ...)

** scintellometry/trials/vlbi_b1919/observations.py
  we store all observations in scintellometry/trials/vlbi_b1919/observations.conf
  structured as a ConfigObj file.
  observations.py parses the .conf file and returns useful objects

** scintellometry/folding/filehandlers.py
  several classes to handle data from the different telescopes
  they act like fits files, so we try and use the PSRFITS definitions
  for the naming conventions of useful quantities

** scintellometry/folding/psrfits_tools.py
  read in the psrfits definition file scintellometry/folding/fitsdef.txt
  and set default values

** scintellometry/folding/fold.py
  general-purpose fold routine. there are still a few if-statements
  that are telescope dependent, but I hope to remove them soon.
moved waterfall and foldspec 'normalize' routine to fold.py
and renamed it 'normalize_counts'
moved waterfall and foldspec 'normalize' routine to fold.py
and renamed it 'count_normalize'
ARO processing works
testing lofar processing now...
took a while, but finally got general-purpose reduction script to work
with lofar data. tested against master and it is consistent.

note: i have not tested coherent dedispersion for lofar data, but
the code is largely copied from fold_lofar.py
added gmrt processing. tested and works.

Note... I need to re-test ARO processing.
A simple commit to confirm that all telescope processing routines are
working (in their default configuration (as copied from aro.py,
gmrt.py, lofar.py)).

Note: rfi_filter_raw and rfi_filter_power are not currently working
because they need to be generalized
removed some debugging statements
reduce_data.py:
added --starttime and --endtime arguments (replacing -nt parameter)

filehandlers.py:
 add 'ntimebins' routine that determine 'nt' given a start and end time
 re-ordered the routines alphabetically
missed a space
fixed some typos
fixed up some typos. removed some unnecessary comments
changed start/finish time to match Olaf's sucessful x-corr span
changed output filename to include processing start/end times
started adding psrfits subint data
started adding subint table data saving functionality
Merge branch 'unify_dr' of https://github.com/aberndsen/scintellometry into unify_dr
added more SUBINT table creation functionality... but still more
work to go
done the FITS coding... now need to test
FITS file output is working, though data-integrity need to be verified