Update StFmsTower and StFmsTowerCluster naming

Change member and method naming in accordance with #18
Rename namespace PSUGlobals to FMSCluster

This naming follows the STAR convention as in #18
Update StFmsPointMaker naming

Change member and method naming in accordance with #18
Further changes to StFmsClusterFitter naming

As discussed in #18
Further changes in StFmsTowerCluster naming

As discussed in #18
Rename max N clusters constant

Closes #18