Encoded-character: resolved error reporting issue, added some syntax error tests and fixed some parsing bugs in the process.

Envelope: <> return path now always matches as the empty string, regardless of the specified address part.

Imapflags: resolved problem of hasflags encountering duplicate flags in flag lists contained in a variable.

Resolved code duplication among commands that use comparators and match-types and found problems in the imapflags extension in the process.

Significantly improved handling of old/corrupt binaries and revised matching implementation in the process.

Working towards improving the handling of currupt binaries: defined multiple exit codes for execution functions and defined trace macro for reporting binary corruptions.

Fixed code emission for extension-defined variables and removed hardcoded paths from include extension.

Testsuite: tested handling of teststuite envelope environment and fixed bugs in the envelope test in the process.