Refactor getBuiltInMacros() to be SBSv1 specific. This are the hard-coded macros misc macros we are adding for SBSv1. For SBSv2, they are retrieved from the sbs config query. Also, clean up some API and comments on public APIS

source.sourcegen.jar = src/
output.sourcegen.jar = bin/
bin.includes = plugin.xml,\
               sourcegen.jar,\
               icons/,\
               META-INF/