prevent even better from loading rvm in sh shells, fix #2612
Merge branch 'master' of github.com:wayneeseguin/rvm
improved installation of mruby, disable rubygems installation, fix #2610
improved installation of opal
cleaning __rvm_conditionally_add_bin_path, update #2609
do not use __rvm_conditionally_add_bin_path after sourcing environment file, fix #2609