Make svn --version (and svnsync --version, etc) tell you if ra_svn has

Make svn --version (and svnsync --version, etc) tell you if ra_svn has
SASL support built in.

(Note that get_description is a private API of the ra_loader, only
used from svn_ra_print_modules, so hard-coding it to the
svn_ra_print_modules output format is OK.)

* subversion/libsvn_ra_svn/client.c
  (RA_SVN_DESCRIPTION): Add a second line about SASL, if available.

* subversion/libsvn_ra/ra_loader.c
  (svn_ra_print_modules): Note that if we change the format of this
   function, ra_svn may need special care.

git-svn-id: http://svn.collab.net/repos/svn/trunk@29625 612f8ebc-c883-4be0-9ee0-a4e9ef946e3a