- jpalomo's A_Saw flags submission.
Merge branch 'master' of https://github.com/rheit/zdoom
- added option to set a sector's tag via compatibility.txt (needed by GZDoom)
- missed a line.
- Fixed: InInventory didn't work quite right with multiple items.
- Added IfHealth based on Blue Shadow's patch.
Added ability to turn off hi-res backing surface rendering on Retina displays

High resolution backing surface is enabled by default and controlled via vid_hidpi CVAR
When it is set to false one pixel per point scale is used
Merge branch 'master' of https://github.com/rheit/zdoom into z_osx_clean