GVL_CONSTANTS (GVL)

InOut:

Scope	Name	Type	Initial	Comment
Constant	MAX_LEVEL_LINE	INT	10	Maximum level lines present
	MAX_LINE_WIDTH	INT	20	Maximum width of level line
	MAX_ZOOM_HEAP	INT	10	Maximum heap size where to store previous zoom level
	MAX_TEXT_REPLACE	INT	100	Maximum available texts for number replacing