Merge pull request #171 from udp3f/master

add useful columns to mendelian disease tools
Clarified the --allow-other-hets option

I understood it to mean that if >1 person was compound het for a pair of variants, the variants were excluded (vs if >1 person is het any variant, that variant is excluded).
Merge pull request #172 from jxchong/patch-3

Clarified the --allow-other-hets option
Typo: can -> can't :)
Merge pull request #174 from jxchong/patch-4

Typo: can -> can't :)
[ENH] allow 0 or -9 in PED for unknown parent
[BUG] auto_dom: if one parent is affected, candidates should solely be in child and said parent.
throw a useful(?) error for invalid queries
remove extraneous commit
[ENH] de_novo; add --filter, --columns, and --gt_filter.; default -d to 0; don't enforce num_het== 1
[ENH] auto_dominant; add --filter, --columns, and --gt_filter.
[ENH] auto_recessive; add --filter, --columns, and --gt_filter.
[ENH] add new options to main
merge conflicts
[DOC] update docs for improvements to auto_* and de_novo tools
fix header
suppress --gt-filter opt. from auto_* et al for now:
[ENH] enhance affected status labelling for parents.
bump version to 0.5.0b
[DOC] add release history