2.2-3
	Fixed a bug in handling of missing data, uncovered by Xiaoyue "Maggie" Niu, and added a test for it.
	Documentation fixes.
2.2-2
	More documentation fixes.
2.2-1
	Documentation fixes.
2.2
	Ability to fit random effects (actor heterogeneity) models.

	Removed ergmm.par class --- it has been rendered obsolete by
	changes in R's handling of partial matching in [[ operator.

	Many bug fixes and miscellaneous changes.
