no new bundless installed => no new bundles installed.

- append slash to indicate directory, so expand ingnores wildignore
settings

- in case bundle has some scripts
- ie Command-T may provide compilation scripts, in that case they should
define augroup bundle#command-t. see test/vimrc for example

- See:
- src/main.c - for plugin loading
- src/ex_cmds2.c - for how :runtime! and :source work

- benefit of using source vs runtime is that it's faster as doesn't
traverse &rtp

- neccessary for custom built scripts to be installed properly

- neccessary for Bundle! configured bundles havin custom settings
- fallback to default behav in case not found

GitHub usernames cannot start with an underscore, but they can be a
single character long.

- just by checking content

Conflicts:

	autoload/vundle/installer.vim

- just by checking content

- closes #21