Squashed 'external/trappy/' changes from a70310cd..aa6f8e2ac64a

aa6f8e2ac64a Merge pull request #288 from valschneider/trappy-hex-cast
9eca88cf9dac base: Fix string to int conversion

git-subtree-dir: external/trappy
git-subtree-split: aa6f8e2ac64aec67acb4c4b4ed89fedfe278bf59