Issue #1511112 by fgm, blueyed and hswong3i: git_deploy slows down module install/enable massively.
Issue #1471178 by sun and hswong3i: Increases security by escaping shell arguments.
Issue #1471178 by sun and hswong3i: Increases security by escaping shell arguments (Part 2).
disable localized git output

Since version 1.8 git outputs some texts in localized versions.
As the module code parses the git output it must not be localized or
module versions are not found.