This module is a 'Bare' XML parser. It is implemented in C. The parser
itself is a simple state engine that is less than 500 lines of C. The
parser builds a C struct tree from input text. That C struct tree is
converted to a Perl hash by a Perl function that makes basic calls back to
the C to go through the nodes sequentially.

The parser itself will only cease parsing if it encounters tags that are
not closed properly. All other inputs will parse, even invalid inputs. To
allowing checking for validity, a schema checker is included in the module
as well.

The schema format is custom and is meant to be as simple as possible. It is
based loosely around the way multiplicity is handled in Perl regular
expressions.