Merge branch 'hotfix/1.25.19'
Update rvm-prompt

Semver compliance.
Merge pull request #2647 from elia/patch-3

Update rvm-prompt
autoupdate on rvm list known, fix #2648
Merge branch 'master' of github.com:wayneeseguin/rvm
added ruby 2.1.1 patches
Merge pull request #2649 from skaes/ruby-2.1.1-patches

added ruby 2.1.1 patches
cleaning install_rvm_step for #2634
add timing to installator debugging, update #2634
Merge branch 'master' of github.com:wayneeseguin/rvm
fix typo, closes #2652
speed up removing files, update #2634
fix removing multiple zeros from seconds string when calculating time difference in installer, update #2634
fix padding of nanoseconds, update #2634
extract cleanup_old_help_and_docs_files in installer instead of writing comments, update #2634
use --local flag for local gems installation - avoid network lookups, update #2634
prevent reinstallation of gem-wrappers when rvm gem missing, update #2634
skip \cat and use shell redirections directly to speed up, update #2634
some directories can be replaced instead of manually coping files, update #2634
speed up checking hook names during installation, update #2634