Add support for search history

- Add `--history` option (e.g. fzf --history ~/.fzf.history)
- Add `--history-max` option for limiting the size of the file (default 1000)
- Add `previous-history` and `next-history` actions for `--bind`
    - CTRL-P and CTRL-N are automatically remapped to these actions when
      `--history` is used

Closes #249, #251

shell/completion.bash

@@ -45,7 +45,10 @@ _fzf_opts_completion() {
     --print-query
     --expect
     --toggle-sort
-    --sync"
+    --sync
+    --null
+    --history
+    --history-max"
 
   case "${prev}" in
   --tiebreak)
@@ -56,6 +59,10 @@ _fzf_opts_completion() {
     COMPREPLY=( $(compgen -W "dark light 16 bw" -- ${cur}) )
     return 0
     ;;
+  --history)
+    COMPREPLY=()
+    return 0
+    ;;
   esac
 
   if [[ ${cur} =~ ^-|\+ ]]; then
@@ -207,7 +214,7 @@ EOF
 }
 
 # fzf options
-complete -F _fzf_opts_completion fzf
+complete -o default -F _fzf_opts_completion fzf
 
 d_cmds="cd pushd rmdir"
 f_cmds="