Editing EDF game properties reference

This unique block changes global game properties from established hardcoded defaults.

==Structure==
 gameproperties
 {
  flags.add <string>
  flags.remove <string>
  missionflags.add <string>
  missionflags.remove <string>
  demo.titletics <integer>
  demo.advisortics <integer>
  demo.pagetics <integer>
  menu.background <string>
  menu.transframe <string>
  menu.skvattacksound <string>
  menu.offset <integer>
  menu.pointer1 <string>
  menu.pointer2 <string>
  border.flat <string>
  border.topleft <string>
  border.top <string>
  border.topright <string>
  border.left <string>
  border.right <string>
  border.bottomleft <string>
  border.bottom <string>
  border.bottomright <string>
  console.charsperline <integer>
  console.bellsound <string>
  console.chatsound <string>
  console.backdrop <string>
  hud.pausepatch <string>
  game.pufftype <string>
  game.telefogtype <string>
  game.telefogheight <integer>
  game.telesound <string>
  game.thrustfactor <integer>
  game.defpclass <string>
  game.endgamefinaletype <string>
  game.skillammomultiplier <floating-point>
  game.monstermeleerange <value>
  game.itemheight <floating-point>
  finale.text.x <integer>
  finale.text.y <integer>
  castcall.title.y <integer>
  castcall.name.y <integer>
  intermission.pic <string>
  sound.defaultmusname <string>
  sound.defaultsndname <string>
  credit.background <string>
  credit.y <integer>
  credit.titlestep <integer>
  exit.endtextname <string>
  game.skillammomultiplier <number>
  blood.defaultnormal <string>
  blood.defaultrip <string>
  blood.defaultcrush <string>
 }

==Description==
===Flags===
*'''flags.add''' and '''flags.remove'''
Adds or removes general gameplay flags from the default set. Group them using the usual syntax, separating them by | (vertical bar), + or "," (comma). For plus and comma, you need to surround all flags in quotes.
====List of flags====
You can use the flags from the following categories:
=====Gameplay=====
These flags control gameplay physics:
:*'''CHASEFAST''': accelerates all the [[Chase]] states of monsters on skill 5 and '''-fast''' like in Heretic.
:*'''HASMADMELEE''': causes all monsters to fight each other when player dies in single player (like in Heretic).
:*'''LOSTSOULBOUNCE''': for demo compatibility, decide whether lost souls should bounce on floors (normally it's a user or [[OPTIONS]] gameplay setting).
:*'''SKILL5RESPAWN''': make monsters respawn on skill 5.
=====Game flow control=====
These flags don't control gameplay per se, but are important for player control and progression:
:*'''DOOMWEAPONOFFSET''': setup weapon frame '''offset()''' attributes to render like in Doom. Necessary for Dehacked compatibility.
:*'''INVALWAYSOPEN''': Inventory is always open (like Strife, but not Heretic).
:*'''MAPXY''': use ''MAPxy'' map names by default. This implies that the '''-warp''' command-line parameter will expect one value, and any legacy features which depended on the ''ExMy'' vs. ''MAPxy'' arrangements will favour ''MAPxy''.
:*'''NODIEHI''': avoid playing the '''pdiehi''' (high) death sound.
:*'''SETENDOFGAME''': [[Teleport_EndGame]] enables the cast finale.
=====Cosmetic=====
These flags control minor display differences between the games. Usually they're of limited use for mod authors, only relevant for the base game differences. Check this list if you have particular issues to solve in your mod:
:*'''CENTERHUDMSG''': make messages always show in center. Typical with Heretic.
:*'''CHEATSOUND''': make the menu sound when cheating.
:*'''HASADVISORY''': display the advisory popup in the title screen. This means drawing an "ADVISOR" lump image at coordinates (4, 160) of a virtual 320x200 screen space, soon as the title screen appears.
:*'''HUDSTARTBARNAME''': displays the automap level name and time relative to the status bar instead of at a hardcoded position.
:*'''IMPACTBLOOD''': '''(unused)'''. Projectiles causing blood on impact is a [[thingtype]] flag now.
:*'''MNBIGFONT''': use big font for menu titles.
:*'''SAVESOUND''': make a sound in save and load menus. This is a small interface detail.
:*'''SHADOWTITLES''': adds shadows font effects to the titles in menus.
:*'''SKILL5WARNING''': warn player if they want to start a new game on skill 5.
:*'''WOLFHACK''': is subject to German-edition restriction on secret levels. Typical for Doom 2.

====Internally preset flags====
The games supported by Eternity start with the following flags preset:
=====Doom=====
Common to all variants: '''DOOMWEAPONOFFSET''', '''HUDSTATBARNAME''', '''SKILL5RESPAWN''', '''SKILL5WARNING'''.

In addition, the following variants of Doom have extra flags:
*shareware: '''NODIEHI'''
*retail (Ultimate Doom): '''LOSTSOULBOUNCE'''
*commercial (Doom II): '''MAPXY''', '''SETENDOFGAME''', '''WOLFHACK'''
:Final Doom, the Xbox and the BFG edition versions also have '''LOSTSOULBOUNCE'''.
=====Heretic=====
For Heretic, the preset flags are: '''CENTERHUDMSG''', '''CHASEFAST''', '''CHEATSOUND''', '''HASADVISORY''', '''HASMADMELEE''', '''MNBIGFONT''', '''SAVESOUND''', '''SHADOWTITLES'''.