travis cl
Rename $source to $src and $dest to $dst

`source` is a terrible name for a variable in shell scripts:
it gets highlighted as a keyword—that's annoying.

Conflicts:
	script/bootstrap
Drop `link_files` function

It had strange name anyway

Conflicts:
	script/bootstrap
Fixing Homebrew URL

The url is outdated
Conflicts:
	homebrew/install.sh
use .md instead
Fix bootstraping broken in #142

Conflicts:
	script/bootstrap
Get rid of long ifs

This commit also preserves observable behaviour

Conflicts:
	script/bootstrap
Check if target exists and is a symlink

Conflicts:
	script/bootstrap
awesomeness