Remove old runtime build system in favor of downloading from repo.steampowered.com/steamrt
and using chroot to build
script to build a runtime
ignore newpkg download directory
add script for creating runtime chroot
remove more obsolete files
update readme
flesh out readme
Minor README fixes

Fixes a typo, clarifies some bits, and fixes the schroot make command.
Merge pull request #19 from jorgenpt/scout

Minor README fixes
Merge pull request #20 from ValveSoftware/scout

Replace old runtime build system with repo.steampowered.com/steamrt repository