Add Bitcoin Package

It seems to be working, except it doesn't install into the profile, see the last comment below for details.


Here is the makefile that is used: https://github.com/bitcoin/bitcoin/blob/03a7d673876dc8fbae876290b455c02b0cac80bd/src/makefile.unix one just has to declare the proper variables.

Here is documentation how to build it: https://github.com/bitcoin/bitcoin/blob/03a7d673876dc8fbae876290b455c02b0cac80bd/doc/build-unix.md

Apparently this has changed in the latest bitcoin git master (not yet released), they use autotools.