Adding support for multiple custom files

Works in a few ways:
 * a single file: --custom foo.py (as before)
 * comma-separated list: --custom foo.py,bar.py
 * multiple custom args: --custom foo.py --custom bar.py

fix plot command to work when standard classes are present

standardize on localhost for local server's name

Note: it's a bit confusing, but we need to copy the link
parameter dicts (since we update them with node info), but we
can share the node dicts. Perhaps we should copy the node
dicts as well...

wrap the title string in quotes so that bash interprets it correctly

The hope is that this will make the results a bit more consistent
when running in a VM environment.

Initial update of README, text files and versions for 2.2.0b0

Multi-link topology support

Fall back to OVSBridge if no controller is available for default switch

This should fix #398 for real; note that if we try to shut down ntpd
right at boot, it doesn't work! ;-(

However, setting the Unix time in the traditional manner using seconds
since 1970 should do the trick!

fix silent failures when rt cannot be assigned - will follow up on this