ratago experimental release v0.3

This release continues to enable tests from the libxslt general suite. Most disabled tests have a comment in the test file indicating the area that needs attention.

Major highlights include stricter parsing, DTD validation of input documents, implementations of xsl:with-param and xsl:message, and better handling of a variety of edge cases.

The command-line execuable now has an -indent option that produces indented output.