tools: ts_uinput: support multitouch protocol type A devices
tools: ts_uinput: support multitouch protocol type A devices

Add preliminary support for protocol type A devices. Still untested. Because
those devices don't report their maximum number of slots (touch contacts),
we add a user option to provide it for us.

Fixes #48

kergoth/tslib,kergoth/tslib,kergoth/tslib,kergoth/tslib