Append, not overwrite CXXFLAGS

Author: AMDmi3

CMakeLists.txt

@@ -52,7 +52,7 @@ FIND_LIBRARY(lib_glew GLEW REQUIRED)
 
 ENABLE_LANGUAGE(ASM-NASM)
 
-SET(CMAKE_CXX_FLAGS "-Wall -Wnon-virtual-dtor -Woverloaded-virtual -pipe -lrt -ldl")
+SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wnon-virtual-dtor -Woverloaded-virtual -pipe")
 SET(CMAKE_CXX_FLAGS_DEBUG "-g -O0 -D_GLIBCXX_NO_DEBUG -DEXPENSIVE_DEBUG")
 SET(CMAKE_CXX_FLAGS_PROFILE "-g -pg -O2")
 SET(CMAKE_CXX_FLAGS_RELEASE "-O3")