Added 2 multi file/dir tests; also "ALL" constant for New

Added a couple of tests to exercise creating a mix of folders and files. 
The first test uses a stream created with NOW, and so it monitors files created after the stream is created.
In the second test, the folders and files are created before the stream. Then stream is created with the ALL option, so it will report events that occurred before the stream existed. 
The ALL option makes it easy to create backup tools able to track file changes without constantly running a file monitor.