Rename Kernal variable labels CurFlg to QtSw and InsCnt to Insrt - those

are their names in the canonical CBM documentation and in the X16 ROM sources.
Also remove their use in the X16 variant of VolksForth

6502/C64/src/vf-sys-c16.fth

@@ -12,8 +12,8 @@ include vf-lbls-cbm.fth
 0ff19 >label BrdCol
 0ff15 >label BkgCol
  053b >label PenCol
-  0cb >label CurFlg
-  0cf >label InsCnt
+  0cb >label QtSw
+  0cf >label Insrt
  0540 >label KeyRep
 
  055d >label PKeys

6502/C64/src/vf-sys-c64.fth

@@ -11,8 +11,8 @@ include vf-lbls-cbm.fth
 0d020 >label BrdCol
 0d021 >label BkgCol
  0286 >label PenCol
-  0d4 >label CurFlg
-  0d8 >label InsCnt
+  0d4 >label QtSw
+  0d8 >label Insrt
  028a >label KeyRep
 
   0cc >label blnsw

6502/C64/src/vf-sys-cbm.fth

@@ -6,7 +6,15 @@
 
 Code con!  ( 8b --)   SP X) lda
 Label (con!     ConOut jsr    SP 2inc
-Label (con!end  CurFlg stx InsCnt stx
+Label (con!end
+\ So far VolksForth switches off quote switch and insert count
+\ after every printed character. This introduces a dependency
+\ on Kernal variables QtSw and Insrt that are undesirable on the
+\ X16 where their addresses may change between Kernal versions.
+\ Therefore we'll try how the system behaves without them on the
+\ X16. Possibly this isn't needed at all, in the end.
+(C64 QtSw stx Insrt stx )
+(C16 QtSw stx Insrt stx )
  1 # ldy ;c:  pause ;
 
 Label (printable?   \ for CBM-Code !

6502/C64/src/vf-sys-x16.fth

@@ -10,8 +10,10 @@ include vf-lbls-cbm.fth
 0feab >label ExtApi
 09f2c >label BrdCol
  0376 >label BkgPenCol  \ aka color
- 0381 >label CurFlg  \ aka qtsw
- 0385 >label InsCnt  \ aka insrt
+\ I'm tentatively removing QtSw & Insrt from the X16 variant;
+\ see comment at the top of vf-sys-cbm.fth
+\ 0381 >label QtSw
+\ 0385 >label Insrt
 
 1 >label RomBank
 0 >label RamBank