Clarify action_init by changing nomenclature from "branch" to "target".
Clarify action_init by changing nomenclature from "branch" to "target".

* contrib/client?side/svnmerge/svnmerge.py
  (action_init): changing nomenclature from "branch" to "target",
    since the merge target could be either a trunk or a branch.  This
    helps prepare for a subsequent patch that corrects & adds logic to
    this function and uses the term "target" consistently.

Patch by:  Luke Call <lacall186@onemodel.org>
Review by: Giovanni Bajo <rasky@develer.com>

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion