A few updates on easylzma

Hello,

I have been using this as a lzlib replacement in a couple of libraries of mine.
Thanks for coding/sharing easylzma : )

Here you have a few updates you might want to integrate:
- updated to lzma sdk 9.22 beta
- removed unused lzma sdk files
- fixed compilation errors if compiled as C++ code

Keep up the good work.
- rlyeh