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

Properly implemented dumping a binary including a list of required extensions and support for extension-specific output.

RECOVERED FROM INCONSISTENCY: developed testsuite and binary dumping and fixed various small issues.

Implemented support for overriding default argument implementations of number, string and string-list.

Properly implemented the code dumper. Dumps are now printed in a stream. The individual opcode and operand implementations no longer use printf()s.

Exported sieve-code-dumper from sieve-interpreter containing all code dumping related implementation. Now to remove all printfs....

Grouped runtime parameters into a single runtime environment and started implementation of result composition/execution.

Changed validator's command syntax validation such that command implementations don't have to call the argument, test and block validation functions explicitly.

Changed argument validation to record the first positional argument into the command context by default. Also furter improved validator's error handling.