Closes #1934

Closes #1627

Changes done to Nonius:
* Moved things into "Catch::Benchmark" namespace
* Benchmarks were integrated with `TEST_CASE`/`SECTION`/`GENERATE` macros
* Removed Nonius's parameters for benchmarks, Generators should be used instead
* Added relevant methods to the reporter interface (default-implemented, to avoid
breaking existing 3rd party reporters)
* Async processing is guarded with `_REENTRANT` macro for GCC/Clang, used by default
on MSVC
* Added a macro `CATCH_CONFIG_DISABLE_BENCHMARKING` that removes all traces of
benchmarking from Catch

Closes #1531

This reverts commit 0c39409da710ede162c873616d7295242ccc4981.

added _SIG macros

Previously they could conflict with user-defined type traits that
were in the global namespace.

Fixes #1548

As explained in issue #1273, `operator&&` and `operator||` should give
a proper compile time error on use instead of the compiler complaining
about them not being defined. This commit adds an `always_false` type in
`catch_meta.hpp` used for implementing a nice `static_assert` for both
of the abovementioned operators.

Closes #1273

support for generating test cases based on multiple template template
types combined with template arguments for each of the template template
types specified

e.g.
```
TEMPLATE_PRODUCT_TEST_CASE("template product","[template]",
			   (std::tuple, std::pair, std::map),
			   ((int,float),(char,double),(int,char)))
```
will effectively create 9 test cases with types:
std::tuple<int,float>
std::tuple<char,double>
std::tuple<int,char>
std::pair<int,float>
std::pair<char, double>
std::pair<int,char>
std::map<int,float>
std::map<char,double>
std::map<int,char>

Tested type is accessible in test case body as TestType
Unique name is created by appending ` - <index>` to test name
since preprocessor has some limitations in recursions

Closes #1454