BUG: fix some missing quotes for STREQUAL IF statements

Modules/TestBigEndian.cmake

@@ -10,9 +10,9 @@ MACRO(TEST_BIG_ENDIAN VARIABLE)
       ${CMAKE_BINARY_DIR}
       ${CMAKE_ROOT}/Modules/TestBigEndian.c
       OUTPUT_VARIABLE OUTPUT)
-    IF(${VARIABLE} STREQUAL "FAILED_TO_RUN")
+    IF("${VARIABLE}" STREQUAL "FAILED_TO_RUN")
       MESSAGE(SEND_ERROR "TestBigEndian Failed to run with output: ${OUTPUT}")
-    ENDIF(${VARIABLE} STREQUAL "FAILED_TO_RUN")
+    ENDIF("${VARIABLE}" STREQUAL "FAILED_TO_RUN")
     MESSAGE(STATUS "Check if the system is big endian")
     IF(HAVE_${VARIABLE})
       FILE(APPEND ${CMAKE_BINARY_DIR}/CMakeError.log 

Modules/UseSWIG.cmake

@@ -65,9 +65,9 @@ MACRO(SWIG_ADD_SOURCE_TO_MODULE name outfiles infile)
   GET_SOURCE_FILE_PROPERTY(swig_source_file_generated ${infile} GENERATED)
   GET_SOURCE_FILE_PROPERTY(swig_source_file_cplusplus ${infile} CPLUSPLUS)
   GET_SOURCE_FILE_PROPERTY(swig_source_file_flags ${infile} SWIG_FLAGS)
-  IF(${swig_source_file_flags} STREQUAL "NOTFOUND")
+  IF("${swig_source_file_flags}" STREQUAL "NOTFOUND")
     SET(swig_source_file_flags "")
-  ENDIF(${swig_source_file_flags} STREQUAL "NOTFOUND")
+  ENDIF("${swig_source_file_flags}" STREQUAL "NOTFOUND")
   SET(swig_source_file_fullname "${infile}")
   IF(${swig_source_file_path} MATCHES "^${CMAKE_CURRENT_SOURCE_DIR}")
     STRING(REGEX REPLACE