Factorize the common code from svn_path_remove_component and svn_path_dirname.  Also, fix a whitespace formatting issue introduced in r10135.  
Factorize the common code from svn_path_remove_component and
svn_path_dirname.  Also, fix a whitespace formatting issue introduced
in r10135.  

Patch by: Klaus Rennecke <kre@tigris.org> 
(Tweaked by me: whitespace fix and docstring addition.)

* subversion/libsvn_subr/path.c
  (previous_segment): New factorized routine that finds the end of the
    previous path segment.
  (svn_path_remove_component, svn_path_dirname): Utilize the newly
    created previous_segment.
  (svn_path_canonicalize): Add whitespace after a while statement.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@850219 13f79535-47bb-0310-9956-ffa450edef68

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