Bug fixes

NOTE: Keep in mind that below changes are relative to Zandronum 3.0

• Backported Zandronum 3.1 Leo's fixes for the tic buffer, unlagged being shifted one tic and P_PlayerThink being called after the previous players had already moved online potentially voiding hitscan attacks.
• Railgun attacks now spawn puffs when hitting floors and ceilings.
• Server pitch limits increased to -90 +90 degrees to remove screen jitter when shooting at higher pitch than the Software renderer allows.
• The server will correctly recognize Freedoom 12.1 iwads and let the player join as long as the iwad is compatible with the one used by server.
• Items that were created during the match will no longer respawn below 3D floors.
• The game will use less resources when not focused in multiplayer (requires using vid_renderinbackground 0).
• Fixed missile translation, scale, fill color, transfer sprite and flags not replicating for newly joined players.
• Linux builds now use SDL sound by default.
• Fixed jerky view when spectating another player whose pitch is below -32 degrees or above 56 degrees (the values were dictated by Software renderer).