Refined the comments in the target start-up files.

Fixed typo errors.  Made the comments consistent across all those files.

libsrc/c16/crt0.s

@@ -1,8 +1,8 @@
 ;
 ; Startup code for cc65 (C16 version)
 ;
-; Note: The C16 is actually the Plus/4 with just 16KB of memory. So many
-; things are similar here, and we even use the plus4.inc include file.
+; Note: The C16 is actually the Plus/4 with just 16KB of memory. So, many
+; things are similar here; and, we even use the plus4.inc include file.
 ;
 
         .export         _exit
@@ -22,7 +22,7 @@
 
 Start:
 
-; Save the zero page locations we need
+; Save the zero-page locations that we need.
 
         ldx     #zpspace-1
 L1:     lda     sp,x
@@ -30,16 +30,16 @@ L1:     lda     sp,x
         dex
         bpl     L1
 
-; Switch to second charset
+; Switch to the second charset.
 
         lda     #14
         jsr     BSOUT
 
-; Clear the BSS data
+; Clear the BSS data.
 
         jsr     zerobss
 
-; Save system stuff and setup the stack
+; Save some system stuff; and, set up the stack.
 
         tsx
         stx     spsave          ; save system stk ptr
@@ -53,20 +53,20 @@ L1:     lda     sp,x
 MemOk:  stx     sp
         sty     sp+1            ; set argument stack ptr
 
-; Call module constructors
+; Call the module constructors.
 
         jsr     initlib
 
-; Push arguments and call main()
+; Push the command-line arguments; and, call main().
 
         jsr     callmain
 
-; Call module destructors. This is also the _exit entry.
+; Call the module destructors. This is also the exit() entry.
 
 _exit:  pha                     ; Save the return code on stack
         jsr     donelib         ; Run module destructors
 
-; Copy back the zero page stuff
+; Copy back the zero-page stuff.
 
         ldx     #zpspace-1
 L2:     lda     zpsave,x
@@ -74,17 +74,17 @@ L2:     lda     zpsave,x
         dex
         bpl     L2
 
-; Store the return code into ST
+; Store the return code into BASIC's status variable.
 
         pla
         sta     ST
 
-; Restore the stack pointer
+; Restore the stack pointer.
 
         ldx     spsave
         txs
 
-; Back to BASIC
+; Back to BASIC.
 
         rts