Support SVN_HTTP_LIBRARY environment variable for specifying which HTTP library should be used.
Support SVN_HTTP_LIBRARY environment variable for specifying which HTTP library
should be used.

* subversion/libsvn_ra/ra_loader.c
  (svn_ra_open3): Use SVN_HTTP_LIBRARY environment variable if it exists.
   Otherwise use http-library configuration option.

*** Reverted in r34979 ***

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