[sdformat] Add urdfdom patch

[rmattes]

commit aac062b429ce5a531d633c0ff695fba234daa26b
Author: Rich Mattes <richmattes at gmail.com>
Date:   Fri May 16 20:24:16 2014 -0400

    Add urdfdom patch

 sdformat-2.0.0-urdfdom.patch |   27 +++++++++++++++++++++++++++
 1 files changed, 27 insertions(+), 0 deletions(-)
---
diff --git a/sdformat-2.0.0-urdfdom.patch b/sdformat-2.0.0-urdfdom.patch
new file mode 100644
index 0000000..b030c89
--- /dev/null
+++ b/sdformat-2.0.0-urdfdom.patch
@@ -0,0 +1,27 @@
+diff -up ./cmake/SearchForStuff.cmake.urdfdom ./cmake/SearchForStuff.cmake
+--- ./cmake/SearchForStuff.cmake.urdfdom	2014-04-16 21:49:40.269514105 -0400
++++ ./cmake/SearchForStuff.cmake	2014-04-16 21:50:31.687724816 -0400
+@@ -50,6 +50,22 @@ if (USE_EXTERNAL_URDF)
+   endif()
+ endif()
+ 
++################################################
++# Find gtest
++find_package(GTest)
++if (GTEST_FOUND)
++  set(GTEST_LIBRARY ${GTEST_LIBRARIES})
++  set(GTEST_MAIN_LIBRARY ${GTEST_MAIN_LIBRARIES})
++  set(GTEST_INCLUDE_DIR ${GTEST_INCLUDE_DIRS})
++else()
++  add_library(gtest STATIC "${PROJECT_SOURCE_DIR}/test/gtest/src/gtest-all.cc")
++  add_library(gtest_main STATIC "${PROJECT_SOURCE_DIR}/test/gtest/src/gtest_main.cc")
++  target_link_libraries(gtest_main gtest)
++  set(GTEST_LIBRARY "${PROJECT_BINARY_DIR}/test/libgtest.a")
++  set(GTEST_MAIN_LIBRARY "${PROJECT_BINARY_DIR}/test/libgtest_main.a")
++  set(GTEST_INCLUDE_DIR "${PROJECT_SOURCE_DIR}/test/gtest/include")
++endif()
++
+ #################################################
+ # Macro to check for visibility capability in compiler
+ # Original idea from: https://gitorious.org/ferric-cmake-stuff/ 
+diff -up ./src/CMakeLists.txt.urdfdom ./src/CMakeLists.txt