Update to latest per-directory-history

See [https://github.com/jimhester/per-directory-history]
Update to latest per-directory-history
add brew-cask plugin
`fc -l 1` instead of `history` in zsh_stats #2501

$HIST_STAMP breaks zsh_stats. see #2501
Makes history-substring-search use term specific up and down buttons. Fixes #2089.
Add new brew cask commands
Merge pull request #1 from KevinBongart/brew-cask

Add new brew cask commands
adding README.md for jsontools
updating README.md
Add check for display list equals nil

Emacs returns either a sequence of availbale displays or nil. Checking
nil fixes this script to work as expected.
bug fix for node pp_json version
updated readme.md and using tab char for formatting with node
adding xargs -0 to node aliases
history-substring-search: bindkey now checks if terminfo is available first.
Fixed typos + made wording more consistent in zshrc.zsh-template
New aliases for 'apt-get' and 'aptitude' as they were overwritten by later aliases
Plugin: Rake-fast: Support both *nix and Darwin
`setopt append_history` is not necessary.

Especially given the inc_append_history option, it is not necessary to
set the (default) append_history option.
Add gem build autocompletion
Added link to wiki page for plugins to README.

The wiki is more readable than going to the plugins directory.