Merge pull request #189 from hagen-i2p/gcc5-makefile

* add gcc 5.* to supported compilers

Makefile.linux

@@ -8,15 +8,17 @@ INCFLAGS =
 ## -std=c++11. If you want to remove this variable please do so in a way that allows setting
 ## custom FLAGS to work at build-time.
 
-# detect proper flag for c++11 support by gcc
+# detect proper flag for c++11 support by compilers
 CXXVER := $(shell $(CXX) -dumpversion)
-ifeq ($(shell expr match ${CXXVER} "4\.[0-9][0-9]"),4) # >= 4.10
+ifeq ($(shell expr match $(CXX) 'clang'),5)
+	NEEDED_CXXFLAGS += -std=c++11
+else ifeq ($(shell expr match ${CXXVER} "4\.[0-9][0-9]"),4) # gcc >= 4.10
 	NEEDED_CXXFLAGS += -std=c++11
 else ifeq ($(shell expr match ${CXXVER} "4\.[7-9]"),3) # >= 4.7
 	NEEDED_CXXFLAGS += -std=c++11
 else ifeq ($(shell expr match ${CXXVER} "4\.6"),3) # = 4.6
 	NEEDED_CXXFLAGS += -std=c++0x
-else ifeq ($(shell expr match $(CXX) 'clang'),5)
+else ifeq ($(shell expr match ${CXXVER} "5\.[0-9]"),3) # gcc >= 5.0
 	NEEDED_CXXFLAGS += -std=c++11
 else # not supported
 	$(error Compiler too old)