Merge pull request Z3Prover#1881 from Z3Prover/revert-1880-c++17

Revert "Made Z3 compile for C++17 with MSVC"

bumping version number by 1 for release tagging

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

Official release Z3 4.6.0

Official release Z3 4.5.0

Official release Z3 4.4.1

Last known pure (Microsoft-only) source in the unstable branch.

Last known pure (Microsoft-only) source in the pure branch.

Official release binary Z3 4.4.0 (Windows x86 and x64).

Z3 4.3.2

fixed clang++ for linux

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>