Merge pull request bombela#234 from madebr/mingw

Build backward-cpp on MINGW

Merge pull request bombela#165 from okeuday/binutils_2.34

Fix for binutils 2.34

Merge pull request bombela#118 from pedronavf/optimizations

Code optimizations

Update travis ci badge to point to official builds

Merge pull request bombela#45 from edisongustavo/master

Add support to find_package(Backward)

Merge pull request bombela#40 from Jiboo/master

Don't append definitions if already cached