Add license
add README (mainly for github)
Proceed with the first testable implementation

The object hierarchy is now more or less complete. XML generating code
is still mostly missing, though.
Add a rough sketch of the parser

- code for the "outer layers" is already present;
- inner parts are still incomplete, but the types needed for this are
  almost finished.
Complete a rough implementation

This is the first version that
- compiles and
- does not raise a PROGRAM_ERROR when called from our test code
  (Bugzilla version query).
Several fixes in the XML parser

We can now ask Bugzilla for its version and read the answer.
Remove debug messages from the parser
Fix XML_Image (RPC_Record)
Handle <int> in addition to <i4>
Fix Message.Payload.Build

We have to wrap parameters inside <params><param>...
Merge branch 'release/0.1.0'