Additional cleanup with libressl

- Use gnu-sed for build as OSX's sed is differnt
- Temporarily import some pkgconfig files
- Use patches from https://svn.hboeck.de/libressl-overlay/dev-libs/libressl/
Migrate packages to libressl

Tested with python package, this commit depends on
https://github.com/hashdist/hashstack/pull/357
Fix M2Crypto to use hashdist libressl