Overhaul

This version of Elision represents a major overhaul.
 - Eva is gone, but will return.
 - A new `NativeCompiler` class handles compilation of native operators, and caches the results.
 - The context cannot (at present) be compiled.  Working on this.
 - Lambdas now preserve their "meta"-ness when converting to De Bruijn indices.
 - All traces of the multi-parser system have been removed.
 - The "autoop" and "autorule" properties default to false.
 - Improved the `Debugger` interface and made is usable from Java.
 - Rules now can have a name (and description and detail).  Replacing a rule with another rules with the same name implicitly removes the older rule.

**Be careful**!  This is really a major overhaul of Elision, and many things may be improved, but some are likely broken.