Simplify CTest.cmake module with ELSEIF

We use ELSEIF to simplify the cascading IF blocks for detecting version
control tools.

Modules/CTest.cmake

@@ -130,19 +130,13 @@ IF(BUILD_TESTING)
   IF(NOT UPDATE_TYPE)
     IF(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/CVS")
       SET(UPDATE_TYPE cvs)
-    ELSE(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/CVS")
-      IF(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/.svn")
-        SET(UPDATE_TYPE svn)
-      ELSE(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/.svn")
-        IF(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/.bzr")
-          SET(UPDATE_TYPE bzr)
-        ELSE(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/.bzr")
-          IF(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/.hg")
-            SET(UPDATE_TYPE hg)
-          ENDIF(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/.hg")
-        ENDIF(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/.bzr")
-      ENDIF(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/.svn")
-    ENDIF(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/CVS")
+    ELSEIF(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/.svn")
+      SET(UPDATE_TYPE svn)
+    ELSEIF(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/.bzr")
+      SET(UPDATE_TYPE bzr)
+    ELSEIF(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/.hg")
+      SET(UPDATE_TYPE hg)
+    ENDIF()
   ENDIF(NOT UPDATE_TYPE)
 
   IF(NOT UPDATE_TYPE)
@@ -156,22 +150,16 @@ IF(BUILD_TESTING)
   IF("${_update_type}" STREQUAL "cvs")
     SET(UPDATE_COMMAND "${CVSCOMMAND}")
     SET(UPDATE_OPTIONS "${CVS_UPDATE_OPTIONS}")
-  ELSE("${_update_type}" STREQUAL "cvs")
-    IF("${_update_type}" STREQUAL "svn")
-      SET(UPDATE_COMMAND "${SVNCOMMAND}")
-      SET(UPDATE_OPTIONS "${SVN_UPDATE_OPTIONS}")
-    ELSE("${_update_type}" STREQUAL "svn")
-      IF("${_update_type}" STREQUAL "bzr")
-        SET(UPDATE_COMMAND "${BZRCOMMAND}")
-        SET(UPDATE_OPTIONS "${BZR_UPDATE_OPTIONS}")
-      ELSE("${_update_type}" STREQUAL "bzr")
-        IF("${_update_type}" STREQUAL "hg")
-          SET(UPDATE_COMMAND "${HGCOMMAND}")
-          SET(UPDATE_OPTIONS "${HG_UPDATE_OPTIONS}")
-        ENDIF("${_update_type}" STREQUAL "hg")
-      ENDIF("${_update_type}" STREQUAL "bzr")
-    ENDIF("${_update_type}" STREQUAL "svn")
-  ENDIF("${_update_type}" STREQUAL "cvs")
+  ELSEIF("${_update_type}" STREQUAL "svn")
+    SET(UPDATE_COMMAND "${SVNCOMMAND}")
+    SET(UPDATE_OPTIONS "${SVN_UPDATE_OPTIONS}")
+  ELSEIF("${_update_type}" STREQUAL "bzr")
+    SET(UPDATE_COMMAND "${BZRCOMMAND}")
+    SET(UPDATE_OPTIONS "${BZR_UPDATE_OPTIONS}")
+  ELSEIF("${_update_type}" STREQUAL "hg")
+    SET(UPDATE_COMMAND "${HGCOMMAND}")
+    SET(UPDATE_OPTIONS "${HG_UPDATE_OPTIONS}")
+  ENDIF()
 
   SET(DART_TESTING_TIMEOUT 1500 CACHE STRING 
     "Maximum time allowed before CTest will kill the test.")