git: set gitconfig push.default to `simple`

This is a better default, and the default in Git 2.0

Fix gh-21
bash: prompt improvements

Port over @alrra's improvements to prompt performance and code
organization.
bash: use alrra's cleanup of bash_profile
Fix homebrew error checking for rsync

Homebrew was complaining when looking for the rsync formula because it's
specified with a URL rather than a known package name. Move the rsync
installation from the main set of Homebrew install checks and steps.

Fix gh-19
Add `.curlrc`, default cURL config

Taken from @alrra's dotfiles
Rename `bash` to `shell`
Update README
bin: add `git-updateall` to batch `git-pull`

Execute `git pull` in every child directory of the current directory.
Used to pull down the latest changes for multiple repositories in a
project.
bin: add script to open files in Google Chrome
git: add alias to fetch GitHub Pull Requests

`git gh-pr 123`: fetch pull request 123 from `origin`, create a branch
called `gh-pr/123` and then check it out.

`git gh-pr 123 different-remote` will do the same but get the pull
request from the specified remote.
bin: rename and move backup excludes file

Use the common dotfile-ignore naming pattern for the backup ignores too.
shell: use `~/.dotfilesrc` for custom `brew`

Rather than messing around with when to load `~/.bash_profile.local` and
always being mindful of whether a custom `brew` PATH has been sourced,
expect the custom path to be set in a new file: `~/.dotfilesrc`. It can
be used for any up-front configuration that is needed, while
`~/.bash_profile.local` continues to be for local Bash overrides and
settings.
shell: explicit export of PhantomJS bin
Update README
dotfiles: change git remote to ssh

Keep things simple and avoid times when GitHub starts asking for
passwords for `https` again.
vim: fix buggy console vim rendering

The `lines` setting has unintended consequences when using vim in a
terminal. The rendering of lines is all messed up. Moving the `lines`
setting to `.gvimrc` fixes the problem.

Fix gh-22
shell: fix custom `brew` sourcin again
shell: minor tidy up of `bash_profile`
shell: increase cURL max-time to 5 mins

60 seconds is far too short; cURL was aborting downloads of binaries
that Homebrew was trying to install.
Install `bash` with Homebrew

Install the latest version of Bash.