Update bruvo.r

Fixed dumb mistake in UPGMA which used to give a higher number of clades than the existant ones.
Updated vignette. Bumped version.
Merge branch 'master' into devel

Conflicts:
	DESCRIPTION
	R/bruvo.r
	vignettes/poppr_manual.Rnw
	vignettes/poppr_manual.pdf
	vignettes/poppr_manual.tex

All fixed