Ignore-this: aa3a3b933a4c89e2ee1f911a7d817509

darcs-hash:f4113722f0acc0f3ab7f60d9e880a8d19ca0292c

* Improved error handling: several ostensibly exceptional
  situations which were previously handled inconsistently (or not
  handled at all) are now reified as condition types and
  restarts, among them new ones: UNENCODABLE-VALUE-ERROR,
  SUBSTITUTE-PRINTED-REPRESENTATION, BIGNUMBER-STRING,
  RATIONAL-APPROXIMATION, PLACEHOLDER.

* Added function DECODE-JSON-FROM-SOURCE.

* Encoding and decoding operations shall henceforth have their
  own default streams, *JSON-OUTPUT* and *JSON-INPUT*.

* It is now permissible to use strings as prototypes.  (String
  prototype is interpreted as the name of the class, interned in
  the current *JSON-SYMBOLS-PACKAGE*.)

* Fixed some bugs (and sources of compiler warnings).

* Fixed some documentation strings, argument naming and
  passing conventions, and return values.

* Fixed some copyright notices.

* Improved implementation of JSON-BIND.

* Put CLOS semantics under conditional compilation guards.

* Advanced the version number to 0.4.0.

darcs-hash:64cf95786ab3b66ac3531570ba62f46e3fa69d08

darcs-hash:5752c23ef8739f0d96dbc9842de890aa1b4e2beb