Work around CRPIX1 bug in protobuf sent in Data key from Manager.

The crpix1 field of the protobuf is populated with 0 instead of
the index for the center channel.  To workaround it I compute
the center channel in the display server simply by calculating
number_channels/2.  number_channels is sent in the Data key
protobuf.
Added file logging and added port argument to command line.

The port must now be specified when the server is started, i.e.:

python ./display_server.py 7777

Log messages are currently written to:
/home/sandboxes/jmasters/display_PRODUCTION/vegasrtdd-server/vegas_display_server.log

Default output level is INFO, which records everything except for debug
level messages.
Changed ZMQ message from error to debug.

Othewise, the log file is overwhelmed with ZMQ messages.
Added signal handling for shutdowns.

SIGINT  : Ctrl-C
SIGTERM : kill -15 <pid>, i.e. from TaskMaster

Besides adding signal handlers the main change was to make
the data-gathering thread a daemon thread so it would be
shut down along with the main thread.
Moved UI code into this repository.

Originally the repositories were seperate to keep the server
and client code independent.  However, they really needed to
keep in sync and often a change in one related to a change in
the other.  The client code is still largely independent and
resides comletely in the static/ directory.  This should make
the code managment easier.
Moved app.css up a directory.  Removed redundant M&C files.

The M&C utility python scripts, protobufs and python protobuf
modules are already in the PYTHONPATH after sourcing /home/gbt/gbt.bash

They are found in /home/gbt/lib/python/
Changed log level of some messages.  Other minor sytax changes.

There were to many messages about manager restarts in the log file
output.  Previously all manager restarts were reported, not just
VEGAS.  Now, only VEGAS restarts should show up in the log file.
Added wrapper script to be run from TaskMaster.

This small script sets up the virtualenv for the server,
then starts it.
Remove log to file, update host and port, catch signals.

The log file isn't needed since a log file is written automatically
to /home/gbt/etc/log/vegas_display_server* when run from TaskMaster.

The host and port in the client JS code were accidentally set to
the development machine, so I reset them for production.

While the python code was catching signals, the wrapper script run
from TaskMaster was not.  I fixed this too.