Add shadow and subtract styles to ACS.

There is a matching pull request for rheit/acs.
Restore shadow renderstyle.

It was accidentally lost in r3085.
Merge branch 'master' of https://github.com/Gaerzi/zdoom
Merge branch 'master' of https://github.com/rheit/zdoom
Merge branch 'master' of https://github.com/coelckers/gzdoom into osx
Fixed crash on attempt to load corrupted data file

Instance of FileReader is no longer destructed when header of data file is valid but complete loading of file fails
Loading of truncated .zip file is the simplest test case
Added simple check for unsupported compression method in .7z files
Added support for LZMA2 compression method in .7z archives

Updated LZMA SDK to version 9.20
http://www.7-zip.org/sdk.html
http://downloads.sourceforge.net/sevenzip/lzma920.tar.bz2
* files are sorted by folder and then by name in Xcode project
- added constants for sound channels 5-7.
Fixed file list in VS2005 project of LZMA library
Fixed compilation with updated LZMA library using Visual Studio
Merge branch 'master' of https://github.com/rheit/zdoom into lzma2
Merge branch 'master' of https://github.com/rheit/zdoom
Merge branch 'master' of https://github.com/coelckers/gzdoom into osx
* fix potential crash on corrupted data files
- don't depend on stdint.h because older MSVC versions do not have it.
Added static RNGseed control
Don't change RNG in demos incase they are static
Make sure use_staticrng is false if not needed