Improve parsing of credentials.csv

Use sed to strip quote marks and tail to chop off header, this way we
can use the credentials file as it is.
Move aws directory
Add pythonbrew loading
Remove minibufexpl submodule

minibufexpl causes issues with fugitive's Gdiff, guess which wins.
Remove circular symlink _vim/_vim
Merge remote-tracking branch 'origin/wfscheper' into wfscheper