Do not include third-party scripts in dotfiles if I can download them instead

[Martinsos]

Currently I include some third-party scripts like git-completion.bash, git-prompt.sh and similar in my dotfiles. This is ok, but instead of keeping them in dotfiles I could download them (for example from github) and that way make sure that I always have the newest version! I would do this download in my install script.

There are also some negative sides to this: what if there is big change in script and my setup gets broken? In that case I could keep copies in dotfiles to revert to.