Version Control With Subversion Source

issue #59 ("'svnsync init' supports a --allow-non-empty flag in
Subversion 1.7")

Issue #79 ("Update 'svnsync sync' and 'svnsync copy-revprops'
syntax and recommendations.")

Issue #132 ("1.7 changes: New program, subcommands, and options")

* en/book/ch05-repository-admin.xml
Break up the "Repository Replication" section into a bit about
svnsync, a (currently empty) bit about svnrdump, and then a common
wrap-up section. In the svnsync section, discuss the
--allow-non-empty and --steal-lock options, and rework some
out-of-date material.