Two mechanical fixes SplitLint found: MVQA, and RSTA for zero

Twenty four places moved Q into A or B by pushing it and popping it back.
That is four bus cycles and two bytes to do what MVQA does in one of each,
and several of them are inside loops - Life, the calculator, int8. Nineteen
more loaded zero with INIA 0d0 where RSTA says the same thing in one byte.

Both are equivalent at the CPU rather than by assertion: RSTA and INIA both
leave Status alone, and PSHQ followed by POPA nets to A = Q with the Stack
Pointer where it started. The one difference is that the pair leaves a copy
of Q in memory just below the Stack Pointer and MVQA does not, which
nothing here reads.

Five recorded outputs moved and every one of them says the change worked:

- 16x16Life fits five more generations into the same cycle budget, the
  first 457 lines identical, because the loop got cheaper.
- Life.sbx is 1409 bytes rather than 1411, in three tests that list it.
- Edit.sbx is 1995 rather than 1996.

That last one broke a check I added this morning, and the hole is worth
recording: the CosmOS README's claim about Edit's size did not have the
word "Edit" on the same line as the number, because the subject was in the
sentence before, so the check that measures quoted sizes skipped it
silently. The sentence now names what it is talking about, which makes it
both checkable and clearer, and the check fails on a wrong number there.

Comments on either half of a replaced pair are carried onto the
instruction that replaces them, so nothing anybody wrote was lost.

Programs/Examples/replCalculator.asm

@@ -18,8 +18,7 @@ repl:
   CALL printString
 
   CALL readNonSpace
-  PSHQ
-  POPA
+  MVQA
 
   ; Q, q, or end-of-file exits.
   INIB 0xFF
@@ -39,14 +38,12 @@ repl:
   BRQ inputError
 
   CALL readNonSpace
-  PSHQ
-  POPA
+  MVQA
   SETD Operator
   STA
 
   CALL readNonSpace
-  PSHQ
-  POPA
+  MVQA
   CALL readHexByteFirst
   SETD RightOperand
   STQ
@@ -98,7 +95,7 @@ readNonSpaceLoop:
   INIB 0x0D
   XOR
   BRQ readNonSpaceLoop
-  INIB 0x00
+  RSTB
   CCF
   ADD
   RET
@@ -108,12 +105,11 @@ readNonSpaceLoop:
 readHexByteFirst:
   CALL clearParseStatus
   CALL hexNibble
-  PSHQ
-  POPA
+  MVQA
   INIB 0xFF
   XOR
   BRQ invalidByte
-  INIB 0x00
+  RSTB
   SHL
   SHL
   SHL
@@ -121,11 +117,9 @@ readHexByteFirst:
   PSHA
 
   CALL readNonSpace
-  PSHQ
-  POPA
+  MVQA
   CALL hexNibble
-  PSHQ
-  POPA
+  MVQA
   INIB 0xFF
   XOR
   BRQ invalidLowNibble
@@ -142,7 +136,7 @@ invalidByte:
   STA
   POPD
   INIA 0xFF
-  INIB 0x00
+  RSTB
   CCF
   ADD
   RET
@@ -157,8 +151,7 @@ hexNibble:
   CCF
   SUB
   BRC tryUpperHex
-  PSHQ
-  POPA
+  MVQA
   INIB 0d10
   CCF
   SUB
@@ -171,8 +164,7 @@ tryUpperHex:
   CCF
   SUB
   BRC tryLowerHex
-  PSHQ
-  POPA
+  MVQA
   INIB 0d06
   CCF
   SUB
@@ -185,8 +177,7 @@ tryLowerHex:
   CCF
   SUB
   BRC badNibble
-  PSHQ
-  POPA
+  MVQA
   INIB 0d06
   CCF
   SUB
@@ -195,14 +186,14 @@ tryLowerHex:
 badNibble:
   POPA
   INIA 0xFF
-  INIB 0x00
+  RSTB
   CCF
   ADD
   RET
 
 decimalNibble:
   POPB
-  INIB 0x00
+  RSTB
   CCF
   ADD
   RET
@@ -223,8 +214,7 @@ lowerNibble:
 
 ; Return Q=0 if Q was 0xFF, otherwise return a nonzero value.
 resultIsInvalid:
-  PSHQ
-  POPA
+  MVQA
   INIB 0xFF
   XOR
   RET
@@ -288,7 +278,7 @@ evaluate:
   INIA 0x01
   STA
   RSTA
-  INIB 0x00
+  RSTB
   CCF
   ADD
   RET
@@ -360,7 +350,7 @@ multiplyLoop:
 multiplyDone:
   SETD Product
   LDA
-  INIB 0x00
+  RSTB
   CCF
   ADD
   RET