[split] Move integral theme to oh-my-fish/theme-integral

https://github.com/oh-my-fish/theme-integral

themes/integral/fish_prompt.fish

-# name: Integral
-function _git_branch_name
-  echo (command git symbolic-ref HEAD ^/dev/null | sed -e 's|^refs/heads/||')
-end
-
-function _upstream_count
-  echo (command git rev-list --count --left-right origin/(_git_branch_name)...HEAD ^/dev/null)
-end
-
-function _git_up_info
-  if [ (_upstream_count) ]
-    set -l count (_upstream_count)
-
-    switch $count
-      case "" # no upstream
-        echo ''
-      case "0?0" # equal to upstream
-        echo ''
-      case "0??" # ahead of upstream
-        echo 'u+'(echo $count | cut -f2)
-      case "??0" # behind upstream
-        echo 'u-'(echo $count | cut -f1)
-      case '???'      # diverged from upstream
-        echo $count 'u+'(echo $count | cut -f2)'-'(echo $count | cut -f1)
-      case '*'
-        echo ''
-    end
-  end
-end
-
-function _is_git_dirty
-  echo (command git status -s --ignore-submodules=dirty ^/dev/null)
-end
-
-function fish_prompt
-  set -l blue (set_color blue)
-  set -l yellow (set_color yellow)
-  set -l normal (set_color normal)
-  set -l green (set_color green)
-
-  set -l arrow "∫"
-  set -l cwd $blue(prompt_pwd)
-
-  if [ (_git_branch_name) ]
-    set -l git_branch (_git_branch_name)
-    set -l git_vs_upstream (_git_up_info)
-
-    if [ (_is_git_dirty) ]
-      set git_info $yellow'('$git_branch "±" "$git_vs_upstream"')' $normal
-    else if [ (_git_up_info) ]
-      set git_info $yellow'('$git_branch "$git_vs_upstream"')' $normal
-    else
-      set git_info $green'('$git_branch')' $normal
-    end
-  end
-
-  echo -n -s $cwd' '"$git_info" $normal $arrow ' '
-end
-
-function fish_right_prompt
-  set -l dark_gray (set_color 222)
-  
-  echo -n -s $dark_gray ' ['(date +%H:%M:%S)'] '
-
-end

themes/integral/readme.md

-## integral
-
-A simple git upstream theme.
-
-#### Characteristics
-
-* Current branch
-* Dirty working directory
-* Working directory
-* Git upstream status
-
-#### Screenshot
-![Integral Screenshot](https://cloud.githubusercontent.com/assets/21774/2715353/70af1520-c50a-11e3-9db3-74933fbb8d91.png)