Revert "Issue #1982502 by greg.1.anderson, jhedstrom, anarcat | dpearceMN: Fixed Correct minor defects in backend invoke that can cause large output problems."

This reverts commit 0d7cd052fdf4075a3457650e1fc541649aab8416.
Issue #1989280 by spiderman: Fixed git checkout [branch] silently fails, branch given in makefile never checked out.

Signed-off-by: Jonathan Hedstrom <jhedstrom@gmail.com>
Leave more breadcrumbs so folks find our tests suite and Travis integration.
Issue #1982502 by greg.1.anderson, Damien Tournoud, anarcat, jhedstrom: Reduce complexity of backend invoke; consider removing concurrency
Issue 2012784 by greg.1.anderson: Fix quoting problem with conf_dir in drush script
Issue #2013775 by clemens.tolboom: Fixed SQLite test fails due to missing semi-colon.
Issue #1896132 by Owen Barton. More informative message when web browser won't start due to bad hostname.
Issue #1896132 by shrop: Fixed Getting 'No graphical display appears to be available, not starting browser.' error with drush qd (core-quick-drupal).