Added a set fish_theme_l_right_prompt true variable to activate the right_prompt for l

Characteristics

- Working directory
- Git branch and dirty state (if inside a git repo)
- Rbenv Ruby Version
- Rbenv Ruby Gemset

use existent plugins as examples in the README.md

closing #397

Fixes a small bug

Fixes https://github.com/fish-shell/fish-shell/issues/1964

Add 'will' theme. (double turnstile ⊨)

Fix for better-alias plugin

Improve Markdown indentation

Fix Markdown list indentation

Allow adding bundler plugin execs in local config.

    set bundler_plugin_execs jekyll mustache

fix basename bug on linux

Fix python version detection in theme bobthefish

Relax the python version matching, so `python` that symlinks to
either major versions (e.g. 2, 3) or minor versions (e.g. 2.7, 3.4)
can be properly detected.

Note that currently both pypy and pypy3 have same display glyph.

Pull down menus in history functions
Readme updated

Fix import for completions

Add root .editorconfig file.

Improve Edan theme design & function naming.

- Rename function "edan-remote" and "edan-local" to "edan-set-remote"
  and "edan-set-local".
- Exchange order of "user" & "host" ( xiloºXiloMac => XiloMacˇxilo )
- Change git dirty mark icon ( [edan-update] ★ => [edan-update]× )

Before:
![Screenshot of theme Edan](https://cloud.githubusercontent.com/assets/215282/5837282/b02c0e5c-a1b8-11e4-914f-f4f05e99880a.png)

After:
![Screenshot of theme Edan](https://cloud.githubusercontent.com/assets/215282/6199938/f67e6a54-b49a-11e4-800b-587a638cfb86.png)

clearance theme should display red prompt if $status != 0

Changed github url from http://raw2.github.com to https://raw.githubusercontent.com.