Fix /bin/sh compatibility issue in install.sh
gitfast: update to upstream v1.8.4

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
don't clobber existing RBENV_ROOT & follow Homebrew's default behavior
Added/modified some useful aliases.
catimg plugin
allow to print an image to the stdout using convert
Fix for virtualenv support - fixes #2328, fixes #2297, resolves #2319
Fixed a dirs bug for catimg
catimg: fix exit without using source
supresses errors from convert whilen converting, as they
are usually just warnings
Add rdmtc alias for rails plugin.
Add support to command "show"
Fixes rvm_prompt_info() in lib/rvm.zsh
Returns false when rvm is not found.
Returns false when rbenv is not found.
Adds chruby_prompt_info dummy function.
Joins ruby prompt files and adds ruby_prompt_info.
Refactors ruby_prompts.zsh
new faster SVN plugin
Adds all other dummy implementations.
Adds documentation.
Renames the file to prompt_info_functions.zsh