rename and mark-as-advanced the following cmake-variable used in func…

…tion print_option:

 CURR_${OPT} -> PRINT_OPTION_CURR_${OPT}
so that the date-project now has the following advanced cmake-variables:
 PRINT_OPTION_CURR_BUILD_TZ_STATIC
 PRINT_OPTION_CURR_USE_SYSTEM_TZ_DB
 PRINT_OPTION_CURR_USE_TZ_DB_IN_DOT

CMakeLists.txt

@@ -11,8 +11,9 @@ option( USE_TZ_DB_IN_DOT "Save the timezone database in the current folder" OFF
 option( BUILD_TZ_STATIC  "Build a static version of library" ON )
 
 function( print_option OPT )
-	if ( NOT DEFINED CURR_${OPT} OR ( NOT CURR_${OPT} STREQUAL ${OPT} ) )
-		set( CURR_${OPT} ${${OPT}} CACHE BOOL "" )
+	if ( NOT DEFINED PRINT_OPTION_CURR_${OPT} OR ( NOT PRINT_OPTION_CURR_${OPT} STREQUAL ${OPT} ) )
+		set( PRINT_OPTION_CURR_${OPT} ${${OPT}} CACHE BOOL "" )
+		mark_as_advanced(PRINT_OPTION_CURR_${OPT})
 		message( "# date: ${OPT} ${${OPT}}" )
 	endif( )
 endfunction( )