Revert "Bug 907840 - Rewrite Makefile to Grunt"

This reverts commit 7d6c65c3377a06ba0345ce098c120d9366c43583 due to bustages in
dist files and JSSHELL benchmark.
Bug 907840 - Rewrite Makefile to Grunt (re-landed). r=stas
Bug 907840 - (follow up) Fix Travis test command