BUG: Remove check for files written by file(WRITE) being loaded.

- CMake 1.8 and below did not do the check but could get in
    infinite loops due to the local generate step.
  - CMake 2.0 added the check but failed to perform it in directories
    with no targets (see bug #678).
  - CMake 2.2 removed the local generate which fixed the problem but
    did not remove the check.
  - Between CMake 2.4 and 2.6.0rc6 the check was fixed to work even
    when no targets appear in a directory (see bug #6923).
  - Bottom line: the check is no longer needed.

Source/cmFileCommand.h

@@ -90,10 +90,6 @@ public:
       "if it does not exist.\n"
       "APPEND will write a message into a file same as WRITE, except "
       "it will append it to the end of the file\n"
-      "NOTE: When using file WRITE and file APPEND, the produced file "
-      "cannot be used as an input to CMake (configure_file, source file ...) "
-      "because it will lead to an infinite loop. Use configure_file if you "
-      "want to generate input files to CMake.\n"
       "READ will read the content of a file and store it into the "
       "variable. It will start at the given offset and read up to numBytes. "
       "If the argument HEX is given, the binary data will be converted to "