[tbs_plugins/Makefile] Re-added the -lrt and -lpthread flags to dsm plugin.

Turns out these are somehow not available within tcpborphserver,
maybe they're not linked in? Not sure.
[tbs_plugins/sma_astro] Minor change to fstop debug printf's.

Basically just rearranged things to be more readable/efficient.
[tbs_plugins/sma_astro] Gave longitude and fstop_freq non-zero defaults.

These correspond to the appropriate values for the SMA and the SMA wideband
correlator IF system.
[tbs_plugins/sma_astro] Inverted the fstop delay tracking values.

This turns out to be necessary in order to get fringes! Not sure
why though...
[tbs_plugins] Added roach.make for compiling directly on a ROACH.
Added some more file types and compile products to .gitignore