A bunch of new build targets and configuration scripts

Configuration tool and new targets for setting everything up from scratch so I can play

new targets: libs, install
configuration: creates env.mk, which does the same as build/config-local.mk but auto-generated (I didn't touch the config-local logic, so both should work fine)

make libs tracks all the needed build artifacts and triggers make -C for each
make install creates a directory structure of everything that ejs and ejs.js.exe need (symlinks), and creates a launcher script for ejs with NODE_PATH set correctly