basic implementation of reading bson from external storage shim
use ReadAtLeast()
fix bounds indexing
shim fixes from CR
basic implementation of reading bson from external storage shim
use ReadAtLeast()
fix bounds indexing
shim fixes from CR
move docsource bits into common
Merge branch 'shim' of github.com:shelman/mongo-tools-proto into shim

Conflicts:
	src/github.com/shelman/mongo-tools-proto/common/db/shim.go
	src/github.com/shelman/mongo-tools-proto/mongoexport/mongoexport.go