Changing the style git uses for merge conflicts

Inspired by a [comment on
quora](http://www.quora.com/Git-revision-control/How-does-git-merge-work)
by Anders Kaseorg.
Adding git completion for bash and zsh

Found it on github in a contrib module.
https://raw.github.com/git/git/master/contrib/completion/git-completion.bash
Needed `-H` flag in the find command for symlinks

Without this flag, the find command would not return the sought for results
Modifying source file pattern to be more inclusive

There are some completion scripts that are tailored to specific shells. Git
completion script for example goes by the filename `git-completion.bash`. These
weren't being included in the results returned by the current version of the
find command.
Including the git prompt helper

This doesn't modify the prompt yet. That will be the next step.
Sourcing scripts earlier in bashrc.

The completions, utilties and prompt scripts were going to be used in later
commands. Hence it was important to get them out of the way as quickly as
possible.
Including git status in the prompt
Long directory names on prompt was getting hard

In tmux when I have thin terminal panes, the prompt would get longer than a
single line. Though there might be other ways to solve the problem, this seems
to be the simplest fix that retains most of the benefits of displaying the
full `cwd` at the prompt.