Update README.textile

Added instructions for installing zsh (due to the problems with first time zsh users)
Update README.textile
Update rvm.plugin.zsh

Ruby 2.1.1 -> Ruby 2.1.2.
Merge pull request #2994 from admpsktt/patch-1

Update rvm.plugin.zsh
Merge pull request #2993 from mittalabhas1/master

Update README.textile
add support to `take' for taking remote urls

Download, extract, and cd into the resulting directory.
add mgalgs theme
Fix gmt compdef

Fix typo: gm -> gmt
mgalgs theme: remove rvm stuff
mgalgs theme: spiffy up the colors, add per-host colors
mgalgs theme: more color spiffy'ing (256 colors)