Added math lib, empty transforms module, moved vec and box to it.
Fixed matrix forward template params.
sqr() is now constexpr.
Fixed some constness on vec/box operator -().
Quiet test runner is now explicit about reporting overlong, but successful tests.
Bashed noisy trace.
Started on matrix.

- A slightly optimized multiplier is tested against the vanilla version.
Merge branch 'master' into transforms
-pthread is correctly passed to gcc-compatible builds again.
Merged from master.