ENH: sort plugin command options alphabetically within inputs, parameters, and output groups
ENH: sort plugin command options alphabetically within inputs, parameters, and output groups

Previous option order was stochastic.

Revert this commit when https://github.com/qiime2/qiime2/issues/70 is fixed.

gregcaporaso/q2cli,jakereps/q2cli,jairideout/q2cli,qiime2/q2cli,gregcaporaso/q2cli,jairideout/q2cli,qiime2/q2cli,jakereps/q2cli