Added a more generic way to push sources that deliver a token stream

independent of the actual input from the file. Change macro handling
to use the new input stack.
Fixed an error in FreeIf: If an unexpected .ENDIF was reached, the
assembler started an endless loop printing error messages.


git-svn-id: svn://svn.cc65.org/cc65/trunk@24 b7a2c559-68d2-44c3-8de9-860c34a00d81

src/ca65/error.h

@@ -123,6 +123,7 @@ enum Errors {
     ERR_CPU_NOT_SUPPORTED,
     ERR_COUNTER_UNDERFLOW,
     ERR_UNDEFINED_LABEL,
+    ERR_OPEN_STMT,
     ERR_COUNT  	      	       	      	/* Error count */
 };
 
@@ -140,7 +141,7 @@ enum Fatals {
     FAT_CANNOT_OPEN_LISTING,
     FAT_CANNOT_WRITE_LISTING,
     FAT_CANNOT_READ_LISTING,
-    FAT_MACRO_NESTING,
+    FAT_NESTING,
     FAT_TOO_MANY_SYMBOLS,
     FAT_COUNT	    	  	      	/* Fatal error count */
 };