add simple/initial version of a debug messaging package.

'glog' is faster/better in many ways, but i really want the
'Chanenl' concept that this exposes.

this isn't doing proper parsing in TestEnable, we should add that.
replace some printfs with our new msg.Channel stuff.
delete some dead typing code.

this (and much more) got rewritten in debug/type.go
gitignore: ignore .gv and .png files.

get generated when looking at CFGs and just pollute our dir.