Implemented positionModifier in tail() - added low level support for scrolling (by default scroll amount is 512 bytes)

Signed-off-by: Daniel (dmilith) Dettlaff <dmilith@verknowsys.com>
 Added panel definitions of interval and scroll size.

Signed-off-by: Daniel (dmilith) Dettlaff <dmilith@verknowsys.com>
Implemented log scrolling in panel (arrows up/down)

Signed-off-by: Daniel (dmilith) Dettlaff <dmilith@verknowsys.com>