Added a '-k' flag for preserving information for a genotype filter.

Instead of simply replacing the entry with a '.', the genotype section
is replaced with a './.', but preserves the rest of the information for
that entry.  

A filtered entry for '-g "DP > 5"' WITHOUT '-k' flag would look like:
.

A filtered entry for '-g "DP > 5" -k' would look like:
./.:30.5931:2:2:79:0:0:0,-0.563566,-3.78195
replaced an accidental removal of a ':' in the argument string for
get_opt_long
Removed the Eclipse files
Merge pull request #57 from josephliccini/master

Added -k flag for keeping info in genotype filtering, instead of a '.'