Add --generate-api-docs to build script
Add --generate-api-docs to build script

Add a new option `--generate-api-docs` that changes the build script to
only do what is required to build the API documentation, skipping the
process of building the full Atom binaries.

andrewleverette/atom,stinsonga/atom,t9md/atom,t9md/atom,atom/atom,liuderchi/atom,stinsonga/atom,Mokolea/atom,stinsonga/atom,Mokolea/atom,atom/atom,t9md/atom,stinsonga/atom,liuderchi/atom,andrewleverette/atom,liuderchi/atom,Mokolea/atom,liuderchi/atom,brettle/atom,PKRoma/atom,atom/atom,brettle/atom,andrewleverette/atom,brettle/atom,PKRoma/atom,PKRoma/atom