Simulate Thunderclock in Slot 4

See the new sample for details/example.

Note that reading 12/24-hour time formats that have colons will not
currently work, as the colons will terminate input and result in
invisible ?EXTRA IGNORED errors.

Fixes #44

cm/basic.js

@@ -44,7 +44,7 @@ CodeMirror.defineMode('basic', function(config, parserConfig) {
     "HPLOT": STATEMENT,
     "HTAB": STATEMENT,
     "IF": STATEMENT,
-    "IN#": UNSUPPORTED,
+    "IN#": STATEMENT,
     "INPUT": STATEMENT,
     "INT": FUNCTION,
     "INVERSE": STATEMENT,