Remove obsolete configure options: --with-ssl, which was used by in-tree
neon builds, and --with-gssapi, which was used when GSSAPI support was in
ra_serf rather than serf itself.

* configure.ac: Remove --with-ssl and --with-gssapi.

* build/ac-macros/gssapi.m4: Remove.

* Makefile.in: Remove SVN_GSSAPI_LIBS, SVN_GSSAPI_INCLUDES, INSTALL_GSSAPI_LIB.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1449023 13f79535-47bb-0310-9956-ffa450edef68