Makes type conversions explicit, if they alter a value

This switch is only active when making a release build.

This switch warns about missing prototypes. It does not warn if
functions are declared static. So this switch encourages the usage of
static whenever possible. This enables the compiler to perform inlining.

CMake: Option was not enabled by default as intended.
Makefile: Flags were not passed when building the tests

And remove special handling of SunOs

Allow for alternative archive tool when using make.