Add define for old shared memory window size

Occasionally an event2Test for an old driver is needed, so we need to be able to map the old memory size. We need to export this first.

Add a meaningful print on driver load/unload

Just so we can see which driver we are running from dmesg.

Deepen data buffer queue and eliminate duplicates

Add changes to fix shortcomings in the existing driver. This should be coupled with a new version of event2.