SDCC:

	This patch adds 

	1. Helpers to cut down the size of C code for function entry. Right
	   now the __enter and __enter_s must be in common memory.

	2. An option --external-banker that keeps 4 byte stack offsets for
	   arguments so the linker can patch up banked binaries. Unbanked
	   code is called via push af call foo pop af


Note: This patch is now mostly obsolete. Feature #1 is mostly integrated
into the mainstream SDCC. Feature #2 is only needed for the ZX128 and has
not yet been ported to a recent compiler



SDLTRS:
	Corrects the handling of the IFF flags on interrupt delivery and
when you do a RETI, which has a subtle difference to a RET. Without these
fixes Fuzix will crash at random on the emulator.

	For more information on the Z80 IFF flags see section 5.3 of Z80
Documented: http://www.z80.info/zip/z80-documented.pdf