Fix up credits a bit, re-lock MD5s and disable DEVELOP.

Many CHROMEs in a map would cause lag with more than 1 player because of what was previously done. This should hopefully solve that

Was playing for every mobj killed on during her death sequence.

Didn't end up needing her work.

# Conflicts:
#	src/d_clisrv.c
#	src/d_clisrv.h
#	src/doomdef.h
#	src/p_user.c

A spike bug no more

Jumping at spikes on FOFs in reverse gravity - most notably in ERZ3 - no longer teleports you downwards into the death pit beneath it.

See merge request !157

Fixed a stupid bug involving jumping at spikes on FOFs in reverse gravity caused by my own incompetence/assumptions.

This reverts commit 6476cf3c, reversing
changes made to 0186b90b.

Appveyor: compile with Mingw32 GCC 4.9.3

Let use an old GCC to compile SRB2

See merge request !112

Last few changes for 2.1.17

what it says on the tin

* Updated version number
* Added LJSonic to credits (and changed how I look in the credits to be less stupid)
* fixed resynching players seeing the host turn into a spectator for no reason

See merge request !155

Otherwise we can't force updates!

Netcode shit

*takes the cookie*

-Added a timeout for game state downloading to prevent definitive join freezes in some cases. The timeout has a minimum value of "jointimeout" and gets higher as the game state grows in size
-If the server tries to kick a joiner who is downloading the game state, they will get a timeout instead, because a regular kick would only happen once the game state has been downloaded
-Added a timeout for player ticcmd packets, again to prevent freezes to happen in some cases
-File/game state downloading is now faster, the speed is controlled by the "downloadspeed" cvar, in packets per tic
-The reason is now properly shown when the server refuses connection
-Changed the default values of "nettimeout" to 10 seconds (previously 15) and "maxsend" to 4 MB (previously 1)
-Added a "noticedownload" cvar that displays a message in the server console when someone is downloading a file

CMake: Fix nasm Linux builds

When compiling under Linux with CMake and nasm/yasm enabled, the operation would fail during linking with undefined symbols related to the tmap files.
This commit adds support for passing flags to the assembler and passes ```-DLINUX``` in order to compile.

After this change, binaries are successfully compiled with either nasm or yasm on Linux systems.
Tested on Ubuntu.

See merge request !153

Added transmaps to non modifying lump list.

CMake: split inline ASM code from vid_copy.s code

See merge request !151