Update docs to reference PyNAST 1.2.1

Fixes #1203.
Merge pull request #1204 from jrrideout/issue-1203

Update docs to reference PyNAST 1.2.1
Merge branch 'master' into issue-1195

Conflicts:
	ChangeLog.md
fixed typo
changed RDP reference to reflect new taxonomy assigner default
updated list of available taxonomy assigners
changed RDP reference to reflect new taxonomy assigner default
changed RDP reference to reflect new taxonomy assigner default
updated commands and parameters file to reflect that RDP is no longer the default assigner
changed RDP reference to reflect new taxonomy assigner default
changed RDP reference to reflect new taxonomy assigner default