Use either -std=c++03 or -std=c++11

No intermediate pseudo-standards should be used when compiling.
The option -std=c++11 is used by default now.
Compile with `make defines=PUGIXML_NO_CXX11` to use -std=c++03 instead.

.travis.yml

@@ -4,9 +4,9 @@ os:
   - linux
   - osx
 env:
-  - DEFINES=standard
-  - DEFINES=PUGIXML_WCHAR_MODE
-  - DEFINES=PUGIXML_COMPACT
+  - DEFINES=PUGIXML_NO_CXX11
+  - DEFINES=PUGIXML_NO_CXX11,PUGIXML_WCHAR_MODE
+  - DEFINES=PUGIXML_NO_CXX11,PUGIXML_COMPACT
 script:
   - make test config=coverage defines=$DEFINES -j2
   - make test config=release defines=$DEFINES -j2

Makefile

@@ -47,9 +47,10 @@ ifneq ($(findstring PUGIXML_NO_EXCEPTIONS,$(defines)),)
 	CXXFLAGS+=-fno-exceptions
 endif
 
-ifeq ($(findstring PUGIXML_NO_CXX11,$(defines)),)
-	# Can't use std=c++11 since Travis-CI has gcc 4.6.3
-	CXXFLAGS+=-std=c++0x
+ifneq ($(findstring PUGIXML_NO_CXX11,$(defines)),)
+	CXXFLAGS+=-std=c++03
+else
+	CXXFLAGS+=-std=c++11
 endif
 
 OBJECTS=$(SOURCES:%=$(BUILD)/%.o)