Revert "Make Repository traffic (publicly) in SvnRevision rather than revnum ints"

That was really wrong, going in the direction of more mutual coupling
between Repository and SvnRevision

This reverts commit 5d89d10abd3800b7cf2cbf88fd7c7b33adc42c8d.

Conflicts:
	src/repository.cpp
	src/repository.h
	src/svn_revision.cpp
Revert "Eliminate unutilized branch rules"

Apparently they weren't unutilized, and the fallback repo started
getting commits again!

This reverts commit 654bd631422d84f9dd141415edc995a4b58d4b0b.