BUG: untested fix for newlines in the output of pkg config

Modules/UsePkgConfig.cmake

@@ -31,13 +31,22 @@ MACRO(PKGCONFIG _package _include_DIR _link_DIR _link_FLAGS _cflags)
     # and if the package of interest also exists for pkg-config, then get the information
     IF(NOT _return_VALUE)
 
-      EXEC_PROGRAM(${PKGCONFIG_EXECUTABLE} ARGS ${_package} --variable=includedir OUTPUT_VARIABLE ${_include_DIR} )
-
-      EXEC_PROGRAM(${PKGCONFIG_EXECUTABLE} ARGS ${_package} --variable=libdir OUTPUT_VARIABLE ${_link_DIR} )
-
-      EXEC_PROGRAM(${PKGCONFIG_EXECUTABLE} ARGS ${_package} --libs OUTPUT_VARIABLE ${_link_FLAGS} )
-
-      EXEC_PROGRAM(${PKGCONFIG_EXECUTABLE} ARGS ${_package} --cflags OUTPUT_VARIABLE ${_cflags} )
+      EXEC_PROGRAM(${PKGCONFIG_EXECUTABLE} ARGS ${_package} --variable=includedir 
+        OUTPUT_VARIABLE ${_include_DIR} )
+      string(REGEX REPLACE "[\r\n]" " " ${_include_DIR} "${${_include_DIR}}")
+    
+
+      EXEC_PROGRAM(${PKGCONFIG_EXECUTABLE} ARGS ${_package} --variable=libdir 
+        OUTPUT_VARIABLE ${_link_DIR} )
+      string(REGEX REPLACE "[\r\n]" " " ${_link_DIR} "${${_link_DIR}}")
+
+      EXEC_PROGRAM(${PKGCONFIG_EXECUTABLE} ARGS ${_package} --libs 
+        OUTPUT_VARIABLE ${_link_FLAGS} )
+      string(REGEX REPLACE "[\r\n]" " " ${_link_FLAGS} "${${_link_FLAGS}}")
+
+      EXEC_PROGRAM(${PKGCONFIG_EXECUTABLE} ARGS ${_package} --cflags 
+        OUTPUT_VARIABLE ${_cflags} )
+      string(REGEX REPLACE "[\r\n]" " " ${_cflags} "${${_cflags}}")
 
     ENDIF(NOT _return_VALUE)