Default jshint file - works out of the box for common rules.

Summary:

Test Plan:

Reviewers:

CC:
make ctrlp have a better default - include MRU
remove listchars - makes things less flat
mvimgitdiff command (show git diffs in macvim)

Summary:

Test Plan:

Reviewers:

CC:
Explain `git difftool` command.

Summary:

Test Plan:

Reviewers:

CC: