Several glyph positioning adjustments.
- SingleAdjustmentPositioningSubtable.as now implements the performLookup function
- HardwareCharacterInstance.as now exposes the applyPositionAdjustmentValue function, which is now responsible for applying value records provided by positioning adjustment tables.
- PairAdjustmentPositioningSubtable1.as, PairAdjustmentPositioningSubtable2.as, SingleAdjustmentPositioningSubtable.as now use the applyPositionAdjustmentValue function of HardwareCharacterInstance.as to apply value records.