Fix for #139
Support command completion.

At least for commands. Options not supported yet.
Commited some debugging code :\
Remove `set -e` from completion file.
Add doc for `notify-list`.
Fix for BSD/GNU `install` flag incompatibility.

In git-hub's makefile, `install` directives that use both -C (copy, do not change modification time if destination is the same) and -d (create directories as necessary) flags at the same time will fail on BSD and BSD derivatives. This is because BSD's `install` does not support simultaneous copy-without-modify and parent directory creation, for whatever reason. GNU's version of `install` does not have this problem, presumably because it doesn't need to be backwards-compatible with whichever original `install` prevented this.

This commit fixes the issue by removing the -C flag outright from the conflicting directives, as it does not add anything significant to the installation process.
Merge pull request #141 from woodruffw/master

install flag modification for compatibility with BSD make
Adding a new experimental installer script
Fix init and add completion (but commented out)
Fix root for zsh
try to fix for zsh again
Make sure we have an absolute path.
Update docs for new installer
s/type -f/type -t/ to check for __gitcomp function

In `lib/git-hub.d/init`, to check for the availability of a `__gitcomp`
Bash function, use `type -t __gitcomp` rather than `type -f __gitcomp`.

From my limited testing, `type -t` appears to give the desired output,
whereas `type -f` would not.
Load Bash compl even if `__gitcomp` already exists

In `lib/git-hub.d/init`, load the Bash completion facilities for `git
hub` regardless of whether the `__gitcomp` Bash function, defined by the
standard Git completion script, was already available without
`lib/git-hub.d/init` needing to source the standard Git completion
script.

Previously, the Bash completion facilities for `git hub` would only be
loaded if `__gitcomp` was not available prior to `lib/git-hub.d/init`’s
execution, which did not seem to me to be the desired behavior.
`lib/git-hub.d/init`: Load Bash compl only in Bash

In `lib/git-hub.d/init`, load the Bash completion facilities for `git
hub` (and for `git`) only if running under Bash (a status which is
assumed to be true if the shell parameter `BASH_VERSION` is non-null).

(Note: the diff is mostly increased indentation; it might look
friendlier with `--ignore-space-change` (`-b`).)
Add basic zsh completion script

Add a basic zsh completion script for `git-hub` and `git hub`, at
`share/zsh-completion/_git-hub`, that, if hooked into the zsh completion
system, simply causes zsh to complete available `git-hub` subcommands
(as listed in `lib/git-hub.d/completion`).
`lib/git-hub.d/init`: Set up zsh compl when in zsh

In `lib/git-hub.d/init`, when executing under zsh, prepend the path
`$GIT_HUB_ROOT/share/zsh-completion` to the zsh array parameter `fpath`, so
that our zsh completion script, which is in `share/zsh-completion`, will be
hooked into the zsh completion system.
init: Search more thoroughly for Git compl script

Previously, in `lib/git-hub.d/init`, when executing under Bash, the
standard Git completion script for Bash was checked for only at the
file-path `/etc/bash_completion.d/git`.

None of my computing devices (whether they run Gentoo Linux, Ubuntu
Linux, Mac OS X (with MacPorts), or — going on an assumption here —
Android) have a `/etc/bash_completion.d/git` file; however, Ingy döt
Net’s Ubuntu system reportedly does have such a file.

Having found, in a Git completion script for zsh (that’s in Git’s
repository, but is different from the standard Git completion script for
zsh that’s in zsh’s repository), a list of file-paths whereat the
standard Git completion script for Bash might be found [1], and also
having found the location of the standard Git completion script for Bash
on my Gentoo, Ubuntu, and Mac systems —

 - `/usr/share/bash-completion/git` (Gentoo),
 - `/usr/share/bash-completion/completions/git` (Ubuntu),
 - `/opt/local/share/bash-completion/completions/git` (MacPorts)

— I’ve extended the section of `lib/git-hub.d/init` concerned with
finding and loading, if necessary, the standard Git completion script
for Bash such that it should check for that script at all the above
file-paths.

[1]: <https://github.com/git/git/blob/4109c28e055dba27d73cefb956bea5e611f66ec0/contrib/completion/git-completion.zsh#L34-L36>
Move `init` script to top level and update docs