Default to only showing the maximum in the waveform view
Fix compilation on platforms where int64_t == long
Move Aegisub modules to aegisub.(module) and add wrapper shims
Add a basic test harness for running Automation tests
Make unicode.lua a proper module and add basic tests

Also drop support for >4 byte sequences as they were eliminated in RFC 3629.
Make utils.lua a proper module with a compat wrapper