basic RSA implementation for when openssl is not available
cleaned up trace code
Use custom libs/cflags when openssl is not found
added the rsa implementation to Makefile.am
Merge remote-tracking branch 'andreas/custom-ssl-libs'
Code constification

Not all code is converted, mostly what is touched by abc's const types.
automatic selection of openssl or local crypto implementation
merged AB's changes
merged with AB's const- changes
bug fixes in rsa
added AES encryption and minor bug fixes
cleaned up configure.ac and a Makefile.am
made allnet_stream_encryption_state explicit in stream.h
Autotools: Centralize build versioning in configure.ac
Autotools: sanitize configure.ac and multiple Makefile.am