add additional m4s for posterity
Merge remote-tracking branch 'origin/master' into kk_m4
Merge pull request #17 from valhalla/kk_m4

add m4s
Merge pull request #18 from valhalla/dwn

pbfgraphbuilder Fixes
Add calss to mark OSM nodes Ids that are being used. Uses 1 bit per Id
to mnimize memory use. Abandoned the idea of using google sparsetable.