Add new port: devel/ada-util (Ada Utility Library)

This Ada05 library contains various utility packages for building
Ada05 applications. This includes:

o A logging framework close to Java log4j framework
o Support for properties
o A serialization/deserialization framework for XML, JSON, CSV
o Ada beans framework
o Encoding/decoding framework (Base16, Base64, SHA, HMAC-SHA)
o A composing stream framework (raw, files, buffers, pipes, sockets)
o Several concurrency tools (reference counters, counters, pools,

fifos, arrays)

o Process creation and pipes
o Support for loading shared libraries (on Windows or Unix)
o HTTP client library on top of CURL or AWS

Ada Util also provides a small test utility library on top of
Ahven to help in writing unit tests.