Create a helper function for parsing externals.
Create a helper function for parsing externals.

* subversion/libsvn_wc/props.c
  (parse_external_parts):  New.  Content just moved from...
  (svn_wc_parse_externals_description3): ...here.  Call the new helper function.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@863660 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,wbond/subversion,wbond/subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion