allow -geometry to specify fullscreen or windowed modes, like PrBoom

This allows strings like "640x480w" to cause the engine to run in a
window, while strings like "1280x800f" cause the engine to run in
fullscreen mode.  This is inspired by the behavior of the PrBoom
-geometry parameter.
i_video: fix an if condition in my previous commit

`else if (f == 'w')` doesn't really secure itself against
uninitialized memory, it still needs to test that `s == 3`.
repair menu fading
Update download URL for source code.

Chocolate Doom isn't hosted on Sourceforge any more.
Merge pull request #447 from chungy/master

allow -geometry to specify fullscreen or windowed modes, like PrBoom
Bump version number to 2.1.0.
add menu item to crispness menu
Upstream fix 1

Same fix applied to wp_torpedo selection in P_PlayerThink must also be
applied to weapon rotation code in g_game
Upstream fix 2

Incorrect field being used to retrieve player names during deathmatch
for "%s killed %s" msg; changed to match disassembly.
Upstream fix 3

Propagation of allegiance from teleport beacons to rebels missing;
verfied positioning of missing assignment against disassembly.
Fix 4: Changing player name on local client

Totally left out one of the two sprintf calls found in HU_Responder
which is responsible for setting the player's name on the consoleplayer
node (other nodes receive it through the chat system).
Ignore loop tags on non-looping substitute tracks.

If a substitute music track is played in a non-looping configuration
(eg. the title screen music), ignore loop tags in the file to be
consistent with other source ports. This fixes a bug that was discussed
on #245.
Ignore metadata loop tags if both are zero.

If LOOP_START and LOOP_END are both set to zero, ignore them. This
is consistent with other source ports.
Proceed by pressing enter at netgame warning screen.

If there's some discrepancy between clients who are to play a game
together, a warning dialog is displayed. To acknowledge this message
and proceed, make the user press enter, not escape, which is
counter-intuitive.

This fixes #453 (thanks Alexandre-Xavier).
strife: Allow inventory items > 255.

The 'inventory' field in ticcmd structures can refer to inventory
values greater than the 8-bit range, so this needs to be transferred
over the network as at least a 16-bit value in order to avoid network
desyncs.

This fixes #454 (thanks Quasar).
Replace strdup() with M_StringDuplicate().

strdup() can theoretically fail and return NULL. This could lead to
a crash or undesirable behavior. Add M_StringDuplicate() which does
the same thing but exits with an error if a string cannot be
allocated.

This fixes #456. Thanks to Quasar for the suggestion.
hicol WIP
Merge branch 'master' of https://github.com/chocolate-doom/chocolate-doom

Conflicts:
	configure.ac
Remove 1280x1000 scaling.

We already have 1280x960, which is the correct aspect ratio. This
means that when running at 1080p the windowboxing borders will be
slightly thicker, but if we're already showing borders anyway, it's
better to at least use the correct aspect ratio.

This fixes #460. Thanks to Doom_user for asking about this on
Doomworld: http://www.doomworld.com/vb/post/1316735
Must allow HU_CHANGENAME in chat_dest range

Verified against disassembly. Otherwise, other side does not see name
changes as anything other than a message.