Add some error handling to markovDictionaryWorker (and add dictionary worker to index.html to avoid caching)
Add some rather ugly performance test code to test.html
HACK: Prevent js keywords in the map from being parsed as native code instead of strings (affects the map array when using chainSize of 1). That is, the word "every", when added to the map and then retrieved from the map, is treated as the function "every()"

hacked by throwing a char (*) in front of the word, (e.g. map["*every"] = N), which is just *stupid* but fixes the issue for now.