Use ag instead of ack

https://github.com/ggreer/the_silver_searcher

* ag is faster than ack
* ag searches all files by default (but still ignores gitignored files). This
  removes the need for ack's `--type-add=` options.
* The command is 33% shorter than ack!

agignore

@@ -0,0 +1,3 @@
+log
+tags
+tmp

bin/replace

@@ -9,4 +9,4 @@ shift
 replace_with=$1
 shift
 
-ack -l $find_this $* | xargs sed -i '' "s/$find_this/$replace_with/g"
+ag -l $find_this $* | xargs sed -i '' "s/$find_this/$replace_with/g"

vimrc

@@ -73,9 +73,10 @@ if filereadable(".vimrc.local")
   source .vimrc.local
 endif
 
-" Use Ack instead of Grep when available
-if executable("ack")
-  set grepprg=ack\ -H\ --nogroup\ --nocolor
+" Use Ag (https://github.com/ggreer/the_silver_searcher) instead of Grep when
+" available
+if executable("ag")
+  set grepprg=ag\ --noheading\ --nogroup\ --nocolor
 endif
 
 " Color scheme
@@ -114,8 +115,6 @@ map <Leader>ct :!ctags -R .<CR>
 " Cucumber navigation commands
 autocmd User Rails Rnavcommand step features/step_definitions -glob=**/* -suffix=_steps.rb
 autocmd User Rails Rnavcommand config config -glob=**/* -suffix=.rb -default=routes
-" :Cuc my text (no quotes) -> runs cucumber scenarios containing "my text"
-command! -nargs=+ Cuc :!ack --no-heading --no-break <q-args> | cut -d':' -f1,2 | xargs bundle exec cucumber --no-color
 
 " Switch between the last two files
 nnoremap <leader><leader> <c-^>

zsh/completion/_ack → zsh/completion/_ag

@@ -1,4 +1,4 @@
-#compdef ack
+#compdef ag
 
 if (( CURRENT == 2 )); then
   if [[ -a tmp/tags ]]; then