Testsuite: added RFC compliance tests for the variables extension and fixed use of wrong default comparator.

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.

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.

Added support for reading an entire stringlist into memory. Also fixed various identical bugs in stringlist-related error handling.

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....

Moved address-part, match-type and comparator code registries from interpreter to binary where they belong.

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.