Add nihstro (a 3DS shader tools suite) as a submodule.

.gitmodules

@@ -4,3 +4,6 @@
 [submodule "externals/boost"]
 	path = externals/boost
 	url = https://github.com/citra-emu/ext-boost.git
+[submodule "externals/nihstro"]
+	path = externals/nihstro
+	url = https://github.com/neobrain/nihstro.git

CMakeLists.txt

@@ -141,6 +141,8 @@ set(INI_PREFIX "${CMAKE_CURRENT_SOURCE_DIR}/externals/inih")
 include_directories(${INI_PREFIX})
 add_subdirectory(${INI_PREFIX})
 
+include_directories(externals/nihstro/include)
+
 # process subdirectories
 if(ENABLE_QT)
     include_directories(externals/qhexedit)