Fix being able to find registry keys for IWADs on Windows 64-bit builds.

git-svn-id: http://odamex.net/svn/root/trunk@4128 b0bcef46-2027-0410-bd56-ab726e9a1d04
Fix instances where the SDL libraries were "found" in Program Files.

git-svn-id: http://odamex.net/svn/root/trunk@4129 b0bcef46-2027-0410-bd56-ab726e9a1d04
Add a new cvar for custom crosshair colors: hud_crosshaircolor

git-svn-id: http://odamex.net/svn/root/trunk@4130 b0bcef46-2027-0410-bd56-ab726e9a1d04
Add red, green, and blue sliders for manipulating hex color variables.

Also add menu options for setting the crosshair color.

git-svn-id: http://odamex.net/svn/root/trunk@4131 b0bcef46-2027-0410-bd56-ab726e9a1d04
Add display menu options for team and enemy colors.

git-svn-id: http://odamex.net/svn/root/trunk@4132 b0bcef46-2027-0410-bd56-ab726e9a1d04
Add colored sliders.

git-svn-id: http://odamex.net/svn/root/trunk@4133 b0bcef46-2027-0410-bd56-ab726e9a1d04
Create a grey slider graphic and a color-square for rgb sliders.

git-svn-id: http://odamex.net/svn/root/trunk@4134 b0bcef46-2027-0410-bd56-ab726e9a1d04