Bug 784841 - Part 2: Implement sandboxing for Python build files; r=ted,glandium This is the beginning of Mozilla's new build system. In this patch, we have a Python sandbox tailored for execution of Python scripts which will define the build system. We also have a build reader that traverses a linked set of scripts. More details are available in the thorough README.rst files as part of this patch. * * * Bug 784841 - Part 2b: Option to not descend into child moz.build files; r=ted

dom/imptests Makefile.in's are autogenerated. See
dom/imptests/writeMakefile.py and bug 782651. We will need to update
writeMakefile.py to produce mozbuild files.