Mac: Add guards to CMAKE_FIND_FRAMEWORK and CMAKE_FIND_APPBUNDLE defaults

The default for `CMAKE_FIND_FRAMEWORK`, defined in `Darwin.cmake` and
`Darwin-icc.cmake`, is now guarded so that it will not override command line
arguments passed by users.

Similarly for `CMAKE_FIND_APPBUNDLE`

Modules/Platform/Darwin-icc.cmake

@@ -106,7 +106,9 @@ SET(CMAKE_Fortran_CREATE_SHARED_MODULE
 
 
 # default to searching for frameworks first
-SET(CMAKE_FIND_FRAMEWORK FIRST)
+IF(NOT DEFINED CMAKE_FIND_FRAMEWORK)
+  SET(CMAKE_FIND_FRAMEWORK FIRST)
+ENDIF()
 # set up the default search directories for frameworks
 SET(CMAKE_SYSTEM_FRAMEWORK_PATH
   ~/Library/Frameworks
@@ -115,7 +117,9 @@ SET(CMAKE_SYSTEM_FRAMEWORK_PATH
   /System/Library/Frameworks)
 
 # default to searching for application bundles first
-SET(CMAKE_FIND_APPBUNDLE FIRST)
+IF(NOT DEFINED CMAKE_FIND_APPBUNDLE)
+  SET(CMAKE_FIND_APPBUNDLE FIRST)
+ENDIF()
 # set up the default search directories for application bundles
 SET(CMAKE_SYSTEM_APPBUNDLE_PATH
   ~/Applications
@@ -125,4 +129,3 @@ SET(CMAKE_SYSTEM_APPBUNDLE_PATH
 INCLUDE(Platform/UnixPaths)
 SET(CMAKE_SYSTEM_INCLUDE_PATH ${CMAKE_SYSTEM_INCLUDE_PATH} /sw/include)
 SET(CMAKE_SYSTEM_LIBRARY_PATH ${CMAKE_SYSTEM_LIBRARY_PATH} /sw/lib)
-

Modules/Platform/Darwin.cmake

@@ -228,9 +228,10 @@ SET(CMAKE_CXX_CREATE_MACOSX_FRAMEWORK
       "<CMAKE_CXX_COMPILER> <LANGUAGE_COMPILE_FLAGS> <CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS> <LINK_FLAGS> -o <TARGET> <SONAME_FLAG> <TARGET_INSTALLNAME_DIR><TARGET_SONAME> <OBJECTS> <LINK_LIBRARIES>")
 
 
- 
 # default to searching for frameworks first
-SET(CMAKE_FIND_FRAMEWORK FIRST)
+IF(NOT DEFINED CMAKE_FIND_FRAMEWORK)
+  SET(CMAKE_FIND_FRAMEWORK FIRST)
+ENDIF()
 # set up the default search directories for frameworks
 SET(CMAKE_SYSTEM_FRAMEWORK_PATH
   ~/Library/Frameworks
@@ -239,7 +240,9 @@ SET(CMAKE_SYSTEM_FRAMEWORK_PATH
   /System/Library/Frameworks)
 
 # default to searching for application bundles first
-SET(CMAKE_FIND_APPBUNDLE FIRST)
+IF(NOT DEFINED CMAKE_FIND_APPBUNDLE)
+  SET(CMAKE_FIND_APPBUNDLE FIRST)
+ENDIF()
 # set up the default search directories for application bundles
 SET(_apps_paths)
 FOREACH(_path