beta version 1.6.6.a

release version 1.6.5

release version 1.6.4. Allow specifying 6 GTR rates and G-T to be zer…

…o (requested by Ben Redelings).

Fix error message with number of threads (reported by David Maddison)

Merge remote-tracking branch 'github/latest' into latest

release version 1.6.3

Fix bug -bnni with -spp by disallowing NNI5. Allow bootstrap with het…

…erotachy +H model

release version 1.6.2

towards fixing refineBootTrees()

Fix thread-unsafe model_info with merging models step (reported by Ma…

…rianne and Karen). Start v1.6.1.a