Merge branch 'issue-186-use-local-pybind' into 'master'

pybind11: Use vendored copy instead of globally installed one.

See merge request !253

libs_required/pybind11/CMakeLists.txt

@@ -84,7 +84,7 @@ if(CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR)
   set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 else()
   set(PYBIND11_MASTER_PROJECT OFF)
-  set(pybind11_system SYSTEM)
+  set(pybind11_system "")
 endif()
 
 # Options