Add option to control explosion of cofactor-term-ite following example by Anvesh

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
Add option to control explosion of cofactor-term-ite following example by Anvesh

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
Merge branch 'unstable' of https://git01.codeplex.com/z3 into unstable