[CMake] Added ThirdParty/jedbrown-cmake-modules.

Contains up-to-date FindPETSc and FindNetCDF.

.gitmodules

@@ -28,3 +28,6 @@
 [submodule "ThirdParty/googletest"]
 	path = ThirdParty/googletest
 	url = https://github.com/google/googletest.git
+[submodule "ThirdParty/jedbrown-cmake-modules"]
+	path = ThirdParty/jedbrown-cmake-modules
+	url = https://github.com/jedbrown/cmake-modules.git

cmake-modules @ f4b0a053

-Subproject commit 75678d1d80e39e2e1b14b2fd6afd0e8823e60b2b
+Subproject commit f4b0a053e53de2f4fc75a36af1dd0eede236fc68

jedbrown-cmake-modules @ 91f96174

+Subproject commit 91f96174a8b3f65e19519fa592b1571391c0e3d0

scripts/cmake/CMakeSetup.cmake

@@ -8,8 +8,9 @@ endif()
 
 # Set additional CMake modules path
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH}
-  "${CMAKE_CURRENT_SOURCE_DIR}/scripts/cmake"
-  "${CMAKE_CURRENT_SOURCE_DIR}/ThirdParty/cmake-modules")
+  "${PROJECT_SOURCE_DIR}/scripts/cmake"
+  "${PROJECT_SOURCE_DIR}/ThirdParty/cmake-modules"
+  "${PROJECT_SOURCE_DIR}/ThirdParty/jedbrown-cmake-modules")
 
 list(APPEND CMAKE_PREFIX_PATH
   $ENV{HOMEBREW_ROOT}             # Homebrew package manager on Mac OS

scripts/cmake/SubmoduleSetup.cmake

@@ -8,6 +8,7 @@ set(REQUIRED_SUBMODULES
     ThirdParty/autocheck
     ThirdParty/cmake-modules
     ThirdParty/googletest
+    ThirdParty/jedbrown-cmake-modules
     ThirdParty/tclap
     ThirdParty/tetgen
     ThirdParty/vtkdiff