Squashed 'deps/ox/deps/jsoncpp/' content from commit 5defb4ed

git-subtree-dir: deps/ox/deps/jsoncpp
git-subtree-split: 5defb4ed1a4293b8e2bf641e16b156fb9de498cc

include/PreventInBuildInstalls.cmake

@@ -0,0 +1,9 @@
+string(TOLOWER "${CMAKE_INSTALL_PREFIX}" _PREFIX)
+string(TOLOWER "${ITK_BINARY_DIR}" _BUILD)
+if("${_PREFIX}" STREQUAL "${_BUILD}")
+  message(FATAL_ERROR
+    "The current CMAKE_INSTALL_PREFIX points at the build tree:\n"
+    "  ${CMAKE_INSTALL_PREFIX}\n"
+    "This is not supported."
+    )
+endif()