ABI Compliance Checker 2.3

Improvements

1. Support for GCC 8
2. Use -fdump-lang-class instead of -fdump-class-hierarchy
3. Use -fdump-lang-raw instead of -fdump-translation-unit
4. Enable internal mangling of C++ funcs for all future GCC versions
5. Added -keep-reserved option to report changes in reserved fields
6. Fixed license to LGPL 2.1

Bug Fixes

1. Fix detection of GCC 7 compiled with --with-gcc-major-version-only
2. Fixed internal mangling
3. Escape braces in regex for compatibility with future Perl 5 versions
4. Redirect stderr of objdump -f to null