fix paths quoting for .ruby-gemset, fix #1786
NEXT: [GH-1786] for 1.19.2
improve detecting PATH= without $PATH, update #1785
NEXT: [GH-1786] for 1.19.2
fix rvm_autolibs_flag in __rvm_parse_args_find_known_flags, update #1785
NEXT: [GH-1785] for 1.19.2
fix detecting not writable cellar in homebrew, fix #1785
NEXT: [GH-1785] for 1.19.2
use rubygems --verbose installation only when --debug or --trace, closes #1772
NEXT: [GH-1772] for 1.19.2
fix 16405e8, update #1772
NEXT: [GH-1772] for 1.19.2
fix forcing --binary for *-head rubies, fix #1788
allow per binary server rvm_verify_downloads_flag, update #1788
fix false positive for deteting PATH=, update #1785
NEXT: [GH-1785] for 1.19.2
NEXT: [GH-1788] for 1.19.2
fix escaping of not necessary rm in strings
Merge branch 'master' into features/centos-epel-repo