version of sinf().

This version is faster (about 25% on x86_64) and works when extreme
optimisation options such as -ffast-math are used.

Apparently g++ 4.5.2 on native mingw32 inserts references to __Unwind_Resume
when exceptions are supported. This function is not present in the g++ 4.4
cross-compiler found in Debian, leading to linker errors when cross-
compiling. So we use the latter to build CppUnit itself.

Another problem arises with g++ 4.4, which is the incomplete stripping of
exceptions when -fno-exceptions is used. Since ExceptionTestCaseDecorator.h
has such code, we protect it with #ifdef __EXCEPTIONS in the meantime.

used on the PS3 platform.

number conversions.

a C macro on some systems (Android NDK, PS3...).

for future array versions.

feature.

the float4x4::identity() method is no longer necessary.