Don't duplicate shims in PATH
tests for rbenv-init
replace tab with spaces
Merge pull request #367 from shoyan/master

replace tab with spaces
fix iterating through paths that have spaces in them

Fixes #344, #196
add tests for exec
fix exec fails for invalid version
hack around the hack around bash `echo`
test completions for exec
add tests for completions
improve detection of completion support for commands

Enable JavasCript, Lua and Erlang scripts to provide completions
Merge remote-tracking branch 'upstream/master' into develop

Conflicts:
	libexec/erlenv-commands
	libexec/erlenv-hooks
	libexec/erlenv-init
	libexec/erlenv-rehash
	libexec/rbenv-completions
	libexec/rbenv-exec
	libexec/rbenv-which