C changestats not exposed from R

[krivit]

The following C terms are defined, and as far as I can tell, they are currently not invoked on the R side. Some of them appear to be vestigial terms before tergm was split out of ergm; some related to bipartite homophily; others I can't identify.

@handcock , @CarterButts , @drh20drh20 , @martinamorris , @sgoodreau , can all of these be removed? They will, of course, remain in the commit history.

changestats_experimental.c:

• b1kappa
• altistar
• altostar
• berninhom
• biduration
• bimix
• bkappa
• degreep
• degreep_by_attr
• degreep_w_homophily
• dissolve
• duration
• b2kappa
• factor
• geodegree
• geospartner
• gwb1
• gwd
• gwdegree706
• gwdegreealpha
• gwdegreelambda
• gwb2
• heideriandynamic
• hiertriad
• hiertriaddegree
• icvar
• idc
• intransitivedynamic
• intransitivity
• kappa
• monopolymixmat
• simmeliandynamic
• spatial
• transitivedynamic
• transitivity
• b1share
• b2share
• gwb2share
• gwb1share

changestats_homoproportion.c:

• homoproportion

changestats_internal.c:

• d_b1degree_edgecov
• d_b2degree_edgecov
• d_b1mindegree_edgecov
• d_b2mindegree_edgecov