The LGPLv3 license is not suitable to our project
as it is not a library, for instance. GPLv3 is still
compatible with our libraries (LGPLv3 for libzmq)
and provides us with roughly the same benefits.

1) This converts all of our public classes into opaque pointers
and add accessor methods to "blindly" convert direct access
into accessor access. This follows more closely the CLASS RFC,
located in http://rfc.zeromq.org/spec:21.

2) All of the public headers are located in include/

3) Added versioning software number in bpm_server_classes.h

This fixes #76 github issue.
This fixes #89 github issue.

This is a first setp into modularizing the source code into
independent components. We would like to move as much as
possible functionality into independent libraries (src/libs).

This will be useful for the libbpmclient library
that needs to know the SMIO opcodes and error codes