A) non-const comparison operators should not exist and should not be
encouraged
B) The logic breaks comparing function pointers certain way
C) It was inconsistent anyway, as it only applied to `==` and `!=`
Closes#925
- this file excluded from the CATCH_CONFIG_DISABLE_MATCHERS path.
- matchers are always compiled in to the impl file
- _THROWS_WITH macros are still available with matchers disabled - but only the ones that take a string
- tests that use matchers have #ifdefs, so the whole SelfTest project can compile with matchers disable.