v3.1.0
Per https://www.gnu.org/software/libtool/manual/html_node/Updating-version-info.html: * Source code has changed, interfaces have changed (e.g. 3_1 namespaces): soversion goes from 29.0.0 to 30.0.0. Also, bump IMATH_TAG to v3.1.1. Signed-off-by: Cary Phillips <cary@ilm.com>