added new features to preprocessor --

* preprocessor.php :
    - implemented defineDefaults(), which defines some global preprocessor constants such as OPERATING_SYSTEM,
        allowing for declarations like '#if OPERATING_SYSTEM == "LINUX"'.
    - implemented internalInitialize() which calls defineDefaults(), and any other init code.
    - added internalDefine(), which is the same as defineHandler(), except the names defined are protected and
        cannot be undefined.
    - added messageDirective(), to display informational messages while preprocessing.
    - messageDirective() supports '#$varaible' syntax, which replaces it with its #define value.
    - added handleVariable(), which processes a '#$var' that was found.
    - added inlineDirective(), which supports a basic inlining definition:
        '#inline funcname,filename.php' will cause the preprocessor to replace calls to funcname() with the
        body of the actual function (inlining).  Right now it only supports calls to functions with no arguments.

    - TODO : code cleanup, some testing code has been left in and some of the new code is messy.

* testcode.php :
    - passing a command line parameter of -d will cause the cache file to be deleted.  for testing.
    - various code changes for code testing.

* testfile.php :
    - extensive changes for testing the various new features, still backwards-compatable.
commited testinclude.txt for testing #include directive.