Improved some odds and ends:
-added a few things to SUFFIX_PATTERN and TO_SUFFIX_PATTERN
-added a new function to handle 'am' and 'pm' more intelligently
-made regex for SUFFIX_PATTERN more compact
-changed GeneralDateParser to infer 'today' when only a time is given (e.g., 'lunch at 4pm')
-including 'chrono_test.html' to show changes and use for future testing.