Added workaround for clang version

CMakeLists.txt

@@ -1,4 +1,4 @@
cmake_minimum_required (VERSION 2.8.10)
cmake_minimum_required (VERSION 2.8.7)

# Without this, the MSVC variable isn't defined for MSVC builds ( http://www.cmake.org/pipermail/cmake/2011-November/047130.html )
enable_language(CXX C)

SetFlags.cmake

@@ -205,6 +205,16 @@ macro(enable_profile)
	endif()
endmacro()

#this is a hack because we can't use cmake 2.8.10 because of travis
macro(get_clang_version)
	execute_process(
		COMMAND "${CMAKE_CXX_COMPILER}" "--version"
		OUTPUT_VARIABLE CLANG_VERSION_OUTPUT)
	message(${CLANG_VERSION_OUTPUT})
	string(REGEX MATCH "version ([0-9]\\.[0-9])" x ${CLANG_VERSION_OUTPUT})
	set(CLANG_VERSION ${CMAKE_MATCH_1})
endmacro()

macro(set_exe_flags)
	# Remove disabling the maximum warning level:
	# clang does not like a command line that reads -Wall -Wextra -w -Wall -Wextra and does not output any warnings
@@ -223,8 +233,9 @@ macro(set_exe_flags)
		add_flags_cxx("-ffast-math")

		if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
			if ("${CMAKE_CXX_COMPILER_VERSION}" VERSION_LESS 3.0)
				message(FATAL_ERROR "MCServer requires clang version 3.0 or higher, version is ${CMAKE_CXX_COMPILER_VERSION}")
			get_clang_version()
			if ("${CLANG_VERSION}" VERSION_LESS 3.0)
				message(FATAL_ERROR "MCServer requires clang version 3.0 or higher, version is ${CLANG_VERSION}")
			endif()
			# clang does not provide the __extern_always_inline macro and a part of libm depends on this when using fast-math
			add_flags_cxx("-D__extern_always_inline=inline")
@@ -236,12 +247,12 @@ macro(set_exe_flags)
			add_flags_cxx("-Wno-error=shadow -Wno-error=old-style-cast -Wno-error=global-constructors")
			add_flags_cxx("-Wno-error=exit-time-destructors")
			add_flags_cxx("-Wno-weak-vtables -Wno-switch-enum")
			if ("${CMAKE_CXX_COMPILER_VERSION}" VERSION_GREATER 3.0)
			if ("${CLANG_VERSION}" VERSION_GREATER 3.0)
				# flags that are not present in 3.0
				add_flags_cxx("-Wno-error=covered-switch-default -Wno-error=missing-variable-declarations")
				add_flags_cxx("-Wno-implicit-fallthrough -Wno-error=extra-semi")
			endif()
			if ("${CMAKE_CXX_COMPILER_VERSION}" VERSION_GREATER 3.1)
			if ("${CLANG_VERSION}" VERSION_GREATER 3.1)
				# flags introduced in 3.2
				add_flags_cxx("-Wno-documentation")
			endif()