Fixes to native tester macros - develop

[arhag]

Change Description

• Fixes to properly support multiple usages of EOSIO_TEST in the same executable.
• The original value of ___disable_output is now properly restored in cases where something is forced to be printed.
• Using !(X == Y) instead of (X != Y) in CHECK_EQUAL to be consistent with REQUIRE_EQUAL. (In case the user defined != operator is not consistently the negation of the == operator for particular types.)
• The unit test failure message now distinguishes whether the failure was due to an early abort of the unit test (e.g. due to REQUIRE_ASSERT, REQUIRE_PRINT, REQUIRE_EQUAL, or a direct call to eosio_assert) or if it the unit test completed but still failed (e.g. due to CHECK_ASSERT, CHECK_PRINT, CHECK_EQUAL). In the former case, there will be an additional text (aborted) added to the end of the failure message.
• Removed the duplicate libnative header files that were deprecated since the base branch will be used for eosio.cdt v1.7.x which is allowed to remove these deprecated files.
• Verbose output in unit tests if passed the -v flag.

API Changes

• API Changes

Documentation Additions

• Documentation Additions

[johndebord]

Looks good.