RVM setting MANPATH will break the system manpath and isn't necessary for looking up manpages for commands in .rvm/bin.
This reverts commit 1f68d64.
Revert "add rvm_man_path to MANPATH, fix #880"
This pull request passes (merged 1e41be0 into ecb2139).
A test for the correct behavior:
man -P true man # status=0;
man -P true rvm # status=0;
Merge pull request #966 from thirtyseven/master
rvm shouldn't set MANPATH
just mentioning #880