LP1999823: Additional growing_buffer function names

LP1999823: Additional growing_buffer function names

If mod_shib is installed on Ubuntu our apache modules will crash
because of a function name collision with libssh. This patch adds
additional names for our growing_buffer manipulation functions so
the modules can use them but the old names are still available for
other users.

Signed-off-by: Jason Boyer <jboyer@equinoxOLI.org>
Signed-off-by: Jeff Davis <jeff.davis@bc.libraries.coop>
Signed-off-by: Galen Charlton <gmc@equinoxOLI.org>