groundwork
Add 'source-map' to dev_bundle and bump dev_bundle version.
(Consider this a preliminary version number, subject to
change, until this branch is actually merged.)
Source maps are generated, but they (1) are only
generated for server targets, not browser targets;
(2) aren't used for anything, (3) can only be generated
by linker (not by, say, coffeescript); (4) are stored 
incorrectly (inline in control files, rather than as
separate files); (5) are wrong anyway (at minimum, they
need to be adjusted for boundary string replacement
during link)

But hey. Source maps.
use a private dev bundle version number
rebase fixups