build: Remove install system and makefiles

I now maintain my home dir as an in-place git repo, so there is no need
for any install system.
macports: Really add /opt/local/{bin,sbin} to PATH

The argument to kw_path_prepend must be a single directory, not
a comma-separated list of directories.
bash: Move bash_completion dir

Move '~/.config/kiwi-bash-comletion' -> '~/.bash_completion.d'.
bash_completion: Source only files that match *.bash
bash_profile: Simply include ~/.bashrc

Remove the fallback path for when ~/.bashrc is missing.
gitignore: Ignore a bunch of toplevel stuff
bash_completion: Source files in fixed order

Use `LC_COLLATE=C ls` to list files for sourcing.
profile: Move profile.d to sensible location

Rename "~/.config/kiwi-profile" -> "~/.profile.d".
bashrc: Include files in fixed order

Sort files with LC_COLLATE=C before including them.
bashrc: Include /opt/local/profile.d/*
bash_completion: Include *.sh as well *.bash

That is, add pattern $HOME/.bash_completion.d/*.sh to list of files to
include.