Global install `grunt-cli` instead of `grunt`

As of Grunt v0.4, you should globally install just the CLI for grunt.

Fix gh-11
bash: Use auto-list TAB completion

Decided I prefer auto-list after all.
bin: In backup script, ask for `sudo` upfront
bash: split 'bash_config' into exports and options

Separate the bash exports and options into distinct files.
bash: Better comment exports; reduce history size

List exports alphabetically. Reduce history size limit to 10000. There
isn't much value in having it excessively large.
bash: keep history of previous shells in new shell
bash: recalculate lines & cols for window resize

After each command, check the window size to ensure that lines and
columns are correctly displayed at the new dimensions.
Add @alrra to acknowledgements
Install `rsync` with Homebrew

Use Homebrew to install a modern version of `rsync`. The default install
on older versions of OS X includes options that aren't part of official
rsync distributions. rsync 3 has support for extended attributes.
bin: Fix `rsync` options in backup script

Rely on options that are found in rsync 3.0 (installed via Homebrew)
in order to have the backup script work on a wider range of OS versions.

Use the `rsync` command directly so that the script doesn't have an
explicit reliance on the command mapping to rsync installed in the
`usr/bin` or Homebrew directory.
Update submodule 'syntastic' to v3.0.0
sync with necolas/dotfiles