v0.2

* Fix some subtle but significant bugs in peak scoring and validation.  These
  were found by comparing greylag and MyriMatch results.  Greylag's results
  are now more similar to those of MyriMatch.

* New program ``greylag-call-proteins`` takes the validated peptide list from
  ``greylag-validate`` and assigns them to specific protein groups using the
  parsimony criterion.

* New filter flags to ``greylag-validate`` to support high-accuracy spectra
  (e.g., Orbitrap).  This should help greylag to more often correctly
  distinguish between, for example, trimethlyation, acetylation, and
  carbamylation.

  The new ``-exact-ptms`` flag supports validation of specific peptide
  modifications, as opposed to the peptide in general (with whatever
  modifications).

  The ``--bootstrap`` flag provides a rough estimation of validation
  variance.

* Better performance on single hosts.

* More documentation.

* Many other bug fixes and improvements.