Parser: Exceptions: Add exceptions specific the DTB binding syntax

The reason why these are necessary is that the test framework (testexamples.py)
checks for failures in the "bad" tests by looking for categories of exceptions.

In order to distinguish the DTB Binding exceptions from the other exceptions and
keep the tests clean, it was necessary to add a new set of exceptions which all derive
from a common base class.

Fix licenses

Pass column and source information to CAmkESError.

Not used as yet.

Allow ParseError to accept a full SourceLocation.

This has no immediate effect for now, but opens the way to using column
information in future.

Consolidate error formating logic in CAmkESError.

Make all CAmkES errors inherit from CAmkESError.

No additional functionality or consolidation as yet.

Refactored parser init commit.