updated .gitignore and fixed Benlitz's voxel vcxproj

.gitignore

@@ -61,6 +61,12 @@ build/vs2010/*.sdf
 build/vs2010/*.suo
 build/vs2010/*.log
 build/vs2010/*.XGD
+build/vs2012/ipch
+build/vs2012/*.opensdf
+build/vs2012/*.sdf
+build/vs2012/*.suo
+build/vs2012/*.log
+build/vs2012/*.XGD
 # Do not exclude anything in external. There is no way to do this recursively
 # but the nesting below is currently one level more than our current max.
 !external/*