Disable threading for projectM visualisation

ProjectM only uses threads to background load presets, which takes next
to no time. Additionally, the synchronization code is utterly broken
making every preset transition an opportunity for a crash.  I'd
recommend never re-enabling them.

xbmc/visualizations/XBMCProjectM/libprojectM/CMakeLists.txt

@@ -58,7 +58,7 @@ endif(BUILD_PROJECTM_STATIC)
 SET_TARGET_PROPERTIES(projectM PROPERTIES VERSION 2.00 SOVERSION 2)
 
 if (APPLE)
-ADD_DEFINITIONS(-DMACOS -DSTBI_NO_DDS -DUSE_THREADS)
+ADD_DEFINITIONS(-DMACOS -DSTBI_NO_DDS)
 set(RESOURCE_PREFIX "Resources" )
 FIND_LIBRARY(CORE_FOUNDATION_LIBRARY CoreFoundation )
 MARK_AS_ADVANCED (CORE_FOUNDATION_LIBRARY)
@@ -68,10 +68,10 @@ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mmacosx-version-min=10.4 -L/opt/local/l
 else (APPLE)
 if (WIN32)
 set (RESOURCE_PREFIX "Resources")
-ADD_DEFINITIONS(-DWIN32 -DSTBI_NO_DDS -DUSE_THREADS)
+ADD_DEFINITIONS(-DWIN32 -DSTBI_NO_DDS)
 else(WIN32)
 set (RESOURCE_PREFIX "share/projectM")
-ADD_DEFINITIONS(-DLINUX -DSTBI_NO_DDS -DUSE_THREADS)
+ADD_DEFINITIONS(-DLINUX -DSTBI_NO_DDS)
 endif(WIN32)
 endif(APPLE)