Changes

Summary

1. Amiga: remove tab_last (details)
2. Amiga: Switch out new tab button for a + tab (details)
3. Amiga: Remove add tab bitmap (details)

Commit c5e1a5a7cf02a0c031fa4fa1c4772c0fd40c277a by chris Amiga: remove tab_last
	frontends/amiga/gui_options.c (diff)
	frontends/amiga/gui.c (diff)
	frontends/amiga/options.h (diff)
Commit b005a5d49fc9fe87cd8b088121b067e9f1db3097 by chris Amiga: Switch out new tab button for a + tab
	frontends/amiga/gui.c (diff)
Commit c3338e7826b710821207de3a608a21a8af0848b3 by chris Amiga: Remove add tab bitmap
	frontends/amiga/gui.c (diff)