halved starting metal

so that you can gather metal / deconstruct objects
   right away
increased default view radius
drew direction arrows in autorobots
Made it easier to build straight-ahead autorobots
Allowed down-bots to dig straight in first 10 tiles
made laser beams much longer
Document dev-build.py a bit more.

This way people wondering "what's the one true build system?"
will have an answer.
refactor developer-readme markup
Merge branch 'master' of https://github.com/elidupree/Lasercake
fix USE_BOOST_CXX11_LIBS