Introduced function, OnPlayerStart modified

A new function translateplayer takes the inters PlaylistIndex and
PlayerIndex as an arguments and returns a sequential integer as a
result. Returns -1 on error.

Modified OnPlayerStart to work with the new enviroment.
Changed more onPlayer* + minor improvements

Changed  OnPlayerStop & OnPlayerEOFWarning to use the translatePlayer
function

Prepared rest of the OnPlayer* procedures with the variable
"playerAddress"

introduced a new "writeError" procedure, which is basically a clone of
"writeDebug" only that it alway prints and the type of message is
"lcError"

Extended Player Check in OnLoad to also switch on buttons if a player is
in state "psPaused"
finished code cleanup #2

finished modifying OnPlayerStateChange, OnPlayerPFLOn & OnPlayerPFLOff
for integration in the new player translation.

Code tested & verified, no errors found
Merge pull request #9 from McCavity/code-cleanup-#2

Code cleanup #2 finished