DOC/BUG: Add missing note to ChangeLog.md

The ChangeLog.md file didn't have any information about
make_distance_histograms being removed from the list of scripts.

[skip ci]
Merge branch 'master' of git://github.com/biocore/qiime into missing-changelog-note

Conflicts:
	ChangeLog.md
Merge pull request #1634 from ElDeveloper/missing-changelog-note

DOC/BUG: Add missing note to ChangeLog.md