two times then removed
fixed errors and added possibility to change repository

- changed `dir_build` from current (`pwd`) to temporary directory
  (using `mktemp -d`)
- change pacapt from remote git repo to wget download in to
  `${dir_build}/pacapt`
- fixed paths for git clone and git submodule init/update

- added possibility to supply git url as first command line argument
  and branch as second (to make it possible to test forks and
  branches)