Convert id_us_a.asm to C
Replace macros EGAWRITEMODE, EGABITMASK, EGAMAPMASK and EGAREADMAP with functions
Remove assembler code in VW_Hlin
Remove assembler code in VW_Bar
Remove unused function VW_SetAtrReg
Remove assembler code in VW_SetLineWidth
Remove assembler code in VW_ClearVideo
Minimize assembler code in VW_UpdateScreen
Convert VW_Plot to C
Convert VW_Vlin to C
Convert VW_DrawTile8 to C
Convert VW_MaskBlock to C
Convert VW_ScreenToScreen to C
Convert VW_MemToScreen to C
Disable unused functions VW_DrawPic2x and VW_MemToScreen2x
Convert VW_ScreenToMem to C