Get rid of globals.asm. Use ::s to export labels between objects.

globals.asm was a hack that:
- gave rgbasm an extra 100k lines to read
- increased reliance on the python preprocessor
- made the makefile a mess
- gave object creation an extra step
- wasn't even necessary

This speeds up build time by at least a third.

text/maps/ss_anne_1.asm

@@ -1,4 +1,4 @@
-_SSAnne1Text1: ; 80c70 (20:4c70)
+_SSAnne1Text1:: ; 80c70 (20:4c70)
 	text "Bonjour!"
 	line "I am le waiter on"
 	cont "this ship!"
@@ -11,7 +11,7 @@ _SSAnne1Text1: ; 80c70 (20:4c70)
 	line "silent type!"
 	done
 
-_SSAnne1Text2: ; 80ce6 (20:4ce6)
+_SSAnne1Text2:: ; 80ce6 (20:4ce6)
 	text "The passengers"
 	line "are restless!"