1.7 bitcoin 0.9.1

Keeping track of Bitcoin 0.9.1. Given the changes, it seems sensible to incorperate them in Dogecoin 1.7. Haven't tested yet, this change requires building most of the dependencies in gitian again.

Changes:

- new OpenSSL version because of Heartbleed vulnerability
- statically built bitcoind for older linux distros with older libc versions.