+ Binaries can now either be built or fetched from Docker, not checked into repo history
+ Tool updater pushes docker images
+ Added git as a tool (the one in centos repos is very out of date)
+ Fixed Docker bashrc
~ Fixed cugr, drcu, and vlogtoverilog builds
~ Update CentOS 7 dependencies
~ Folded fetch_submodules into utils.py
~ Assorted Makefile Tweaks