Merge branch 'hotfix/1.25.3'
fix detecting scripts base in zsh, fix #2444, update #2434
do not change executable rights for binaries if already can execute, fix #2445
improve message for __rvm_remove_ruby
improved ruby installation
improve finding installed rubies when list is given, update #2446
make migrate iterate over all gemsets. cleaning code, update #2446
fix selecting rubies for installation
cleaning migration process to avoid problems, update #2446
make sure the migtrated environment and wrappers point to new gemset, fix #2446
fix loading rvm in installer, fix #2447, update #2444
add rvm gemset reset_env, update #2446
1.25.4
Merge branch 'master' into hotfix/1.25.4
Merge branch 'hotfix/1.25.4' into stable