backport Hash#reject regression fix for 2.1.0-railsexpress and 2.1.1-railsexpress
Merge pull request #2713 from skaes/hash-reject-regression-fix

backport Hash#reject regression fix for 2.1.0- and 2.1.1-railsexpress
Indented code blocks in help/tools.md

Markdown expects 4 spaces of indentation for code blocks.
Merge pull request #2716 from tobiashm/patch-1

Indented code blocks in help/tools.md
separate sed commands, update #2709
Merge branch 'master' of github.com:wayneeseguin/rvm
simplifying sed, update #2709