Replaced builtin macro packages with .mac files that are included like ordinary .inc files.

The benefits are:
- Independency of ca65 build from perl
- More transparent behaviour

asminc/cbm.mac

@@ -0,0 +1,62 @@
+; Convert characters to screen codes
+
+; Helper macro that converts and outputs one character
+.macro _scrcode char
+        .if (char >= '@' .and char <= 'z')
+                .byte   (char - '@')
+        .elseif (char >= 'A' .and char <= 'Z')
+                .byte   (char - 'A' + 65)
+        .elseif (char = '[')
+                .byte   27
+        .elseif (char = ']')
+                .byte   29
+        .elseif (char = '^')
+                .byte   30
+        .elseif (char = '_')
+                .byte   31
+        .elseif (char < 256)
+                .byte   char
+        .else
+                .error  "scrcode: Character constant out of range"
+        .endif
+.endmacro
+
+.macro  scrcode arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9
+
+        ; Bail out if next argument is empty
+        .if     .blank (arg1)
+                .exitmacro
+        .endif
+
+        ; Check for a string
+        .if     .match ({arg1}, "")
+
+                ; Walk over all string chars
+                .repeat .strlen (arg1), i
+                        _scrcode        {.strat (arg1, i)}
+                .endrepeat
+
+        ; Check for a number
+        .elseif .match (.left (1, {arg1}), 0)
+
+                ; Just output the number
+                _scrcode        arg1
+
+        ; Check for a character
+        .elseif .match (.left (1, {arg1}), 'a')
+
+                ; Just output the character
+                _scrcode        arg1
+
+        ; Anything else is an error
+        .else
+
+                .error  "scrcode: invalid argument type"
+
+        .endif
+
+        ; Call the macro recursively with the remaining args
+        scrcode arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9
+.endmacro
+
+