Record Java threads automatically

[ahtrotta]

Current behavior is that new threads spawned from the main thread will not record anything.

Detect when a thread starts and begin recording then. Take care not to overwhelm the filesystem with thousands of AppMaps in the case where there’s a large thread pool processing lots of messages per thread.

[kgilpin]

I don't know that this will be satisfactory to the user, unless the data can all be merged into one view somehow. Otherwise it's not clear how the user will find, open, and interpret the additional AppMaps.