exchange: move bundle specification parsing from cmdutil...
exchange: move bundle specification parsing from cmdutil
Clone bundles require a well-defined string to specify the type of
bundle that is listed so clients can filter compatible file types. The
`hg bundle` command and cmdutil.parsebundletype() already establish the
beginnings of a bundle specification format.
As part of formalizing this format specification so it can be used by
clone bundles, we move the specification parsing bits verbatim to
exchange.py, which is a more suitable place than cmdutil.py. A
subsequent patch will refactor this code to make it more appropriate as
a general API.
