Update to playtest_beta

Additions/Changes:

• Added volume cvars for different sound types: snd_ambientvolume, snd_weaponvolume_player, snd_weaponvolume_overall, snd_uivolume, snd_physicsvolume, snd_footstepsvolume

• Log messages now contain a prefix indicating which module the message originated from

• Panorama's Slider and SlottedSlider have been merged (Now just called Slider)

• Added DualSlider widget

Hammer changes/fixes:

• Brought in several smaller dialogs from Qt dialogs GitHub repo (Go to coordinate, Go to brush)

• Fixed Qt windows not having an icon (https://github.com/StrataSource/Engine/issues/233 )

• Fixed crash when validating instances (https://github.com/StrataSource/Engine/issues/243 )

• Fixed crash when opening model browser for models that don't have a skin parameter (https://github.com/StrataSource/Engine/issues/230 )

• Fixed crash when opening model browser with invalid model name (https://github.com/StrataSource/Engine/issues/185 )

• Fixed hammer crash when running in WINE

• Fixed weirdness in file open dialogs

• Fixed "wait for keypress" not saving in expert compile (https://github.com/StrataSource/Engine/issues/236 )

General fixes:

• Fixed native functions returning vector by value returning garbage in VScript (https://github.com/StrataSource/Engine/issues/50 )

If you have opened any of the linked issues above, check if it has a "Needs Testing" label. If it's still open and has this label, please try to verify the fix and close the issue once it's verified