new clones
Raiden II (US, set 2) [farzeno]

also attempted to identify regions / rename sets to fit.

interestingly the 'easy' sets do not show a JAPAN message even when the region is 0x00 (or when the region is 0x04, which is the Korean region on RDX)
correct color prom resistors
(nw)
New games added as GAME_NOT_WORKING
-----------------------------------
Sengoku Basara X Cross [darksoft, Guru]
Kinnikuman Muscle Grand Prix 2 [darksoft, Guru]
Gundam vs. Gundam Next [darksoft, Guru]
added generic cartslot / ROM socket slot device, which offers
basic allocation and access handlers, and converted a few 
drivers to use this instead of code from cartslot.c [Fabio Priuli]

out of whatsnew: the RAM socket part is just a proof of concept,
and the natural extension of the line of thought which lead me
to this generic socket/cartslot. it might allow to convert current RAM 
device to be a slot device as well (after some refactorization, of 
course, since current code lacks many of the necessary features), 
or be removed soonish, depending on consensus.
Add width/endianness to supracan software list [Alex Jackson]
softlist: restored the support for loading games from compatible
softlists (like gbcolor games in gameboy, and viceversa, msx1
carts in msx2, etc.) by using the syntax
  mess system -media list:gamename 
You can now for instance use again "mess gbcolor -cart gameboy:sml"
to play "Super Mario Land" with the custom palettes of the Game 
Boy Color. [Fabio Priuli]
by request, save states (nw)
mark save as supported, seems to work now (nw)

(I think at this point we should go over the source and flip the flag to GAME_NO_SAVE for drivers lacking support, rather than having to flag it when it works, also maybe add the ability to tag devices so if a driver is using a device without support it will automatically inherit that state)
better fix. nw.
itgambl2: De-insanify the address map, fixes MT5493 (nw)
missed these (nw)
NS8250 Fixes [smf]
Loopback: tx goes high and data is clocked at the correct rate instead of appearing instantly
Modem status register: don't lose track of external signals when starting, resetting, switching loopback off, writing to register
Handshaking: active low for consistency (RS232 port now defaults handshaking lines high and serial mouse dtr/rts handling has been adjusted).
Amiga: Silence keyboard log spam and fix internal ROM filename
Amiga: Fix Amiga 600 IDE hard disk regression
(MESS) a2600.c: fixed mapper 3E support, as used by Boulder Dash
homebrew. Also allowed bankswitch writes to get to the TIA for this and 
mapper 3F. Finally, included a couple of demos in the softlist so to be
able to test the code in future. nw.
nw
disabled references to non-existent software lsits (nw)
If we were documented, we'd be dangerous (nw)
added an msx1 YGW game for fun