KYRA: minor cleanup

(rename some variables in Screen::drawShape for better readability)
KYRA: (EOB) - minor cleanup of shape drawing code
AUDIO: (FM-TOWNS) - cleanup euphony code

(rework parts of the code + improve naming of variables/functions)
AUDIO: (FM-TOWNS) - fix looping pcm sounds
AUDIO: (FM-TOWNS) - add error codes
KYRA: (EOB) - add support for FM-TOWNS version

- add static resources and detection entries
- add some startup code so that the game at least boots up without crashing