This is a partial revert of b7b346c3e5603.

The old code caused warnings to fire under MSVC, and Clang <3.8.
I could not find a GCC version where it worked, but I assume that it
did at some point.

This new code causes all of MSVC, GCC, Clang, in current versions,
to emit signed/unsigned comparison warning in test like this:

```cpp
TEST_CASE() {
    int32_t i = -1;
    uint32_t j = 1;
    REQUIRE(i != j);
}
```

Where previously only MSVC would emit the warning.

Fixes #1880

C++11 math requires _GLIBCXX_USE_C99_MATH_TR1 to be true with gcc/clang.

Also fixes an issue with uClibc-ng where __UCLIBC__ is defined in features.h but
that is not included here and is thus no-op.

Fixes #1806

Previously, each warning suppression was self-contained, with its
own pair of `SUPPRESS_X_WARNING` and `UNSUPPRESS_X_WARNING` macros.
This had the obvious advantage of being self-containing, but it
also meant that if we needed to suppress more than one warning
in a single place, then we would manipulate the compiler's warning
state multiple times, even though logically we would only need one
layer.

The new way of suppressing warnings in macros is to push compiler's
warning state with `CATCH_INTERNAL_START_WARNINGS_SUPPRESSION` macro,
then disable whatever macros we need with the
`CATCH_INTERNAL_SUPPRESS_X_WARNINGS` macro, and then return to the
previous state using `CATCH_INTERNAL_STOP_WARNINGS_SUPPRESSION`.

this warning was introduced by rework to support NTTPs
since we have implementation macro for NTTPs and normal template test cases
warning is going to be suppressed

Fixes #1762

Luckily, the rest of C++11 features seem to be supported...

Closes #1739

This is done via the new compile time toggle,
`CATCH_CONFIG_ANDROID_LOGWRITE`.

Closes #1743

Closes #1693