Finish issue #80 ('ch04: Incorrect definition of revision').
* src/en/book/ch04-branching-and-merging.xml (svn.branchmerge.using): Make language about revisions consistent with that in svn.basic.in-action.revs.
Authored by: ptburba@gmail.com 2011-07-07
Parent: [r3895]
Child: [r3897]
