Minor non-logic docstring tweaks.
Minor non-logic docstring tweaks.

* subversion/include/svn_props.h
  Replace usages of "propname" with "prop_name" or with more readable
  text, as appropriate, for consistency and comprehensibility.

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