Add doc/hacking to index
Update comments in mirrors.c for new methods
Add reduce method to built-in lists
Add methods to JS mirrors module to match native
Correct size of mgcollections sets
Add special case for StandardPrelude.new
Allow block information to be persisted to runtime

With this commit, the compiler (and dialects) can annotate a block with
an extra piece of information which will be available at runtime with
the extraRuntimeInformation method on the block. Where this annotation
was not given, this method does not exist.
Fix shadowing in logo_example
Remove old try-else/forceError methods

Proper exception handling has now been implemented according to the
specification, and these can be replaced in code with
catch()case()...()finally and Error.raise.
Remove old matchesBinding code from JS
Fix runtime exception/segfault in method calls
added linenumber method to ExceptionPacket, started adding backtrace
merge; change in comments only
provided access to excpetion packet data via Grace methods. Changed direction of backtrace so that most recent frames come first.  Removed die and replaced calls with gracedie (the two functions being identical)