Revert "Bug 945553 - Rewrite install-gaia.py to install-gaia.js"

This reverts commit b9129ad69a9ea91fda0c3f4c626c2f2eaf15d230.
Merge pull request #14876 from KevinGrandon/revert_bug_945553

Revert "Bug 945553 - Rewrite install-gaia.py to install-gaia.js"