Add options: --prompt and --print-query

Make the list scrollable

- Suppress warning message on Ruby 1.8.5
- Remove unnecessary code

Add vi-command keymap mappings

fzf does not currently define vi-command mode mappings. This is particularly annoying for <C-r>, which opens bash's old-fashioned recursive history search.

This patch adds vi-command mode mappings that simply drop back into vi-insert mode ("i") and then trigger the primary mapping.

Use `command find` rather than plain `find`

Aliases are expanded in shell scripts, and one may have an alias
for the `find` command that conflicts with fzf. So make sure fzf
is using real find command rather than the alias.

Search is interrupted when the query string has changed. This frequently
happens when the user is actively typing in a query. This (rather
arbitrary) delay is introduced not to start the next search immediately,
which is likely to be interrupted as well. The result of it is that fzf
feels more responsive.

As discussed in #55

As discussed in #54

See: ftp://ftp.vim.org/pub/vim/patches/7.4/7.4.260

We have iconv.

[zsh-keybinding] Remove tailing substitution

Fix fzf-history-widget to strip `*` from history lines when using tmux and fc

Update sed regex to strip "*" from history lines when using tmux and fc
e.g. "637* ls -a"

Fixes the problem reported by @elemakil. For some reason unknown,
sometimes the escape sequences of arrow keys are prefixed by 27-79
instead of the ordinary 27-91.