Help: Use consistent levels for cmake --loglevel and message()

The message() command requires uppercase log levels. Even
though the cmake --loglevel option is not case sensitive, show
the supported values as uppercase to match the message()
docs as closely as possible, since they are related to the same
feature.

Also fixes the wrong string being shown for the warning level
by cmake --help.

Help/manual/cmake.1.rst

@@ -200,11 +200,11 @@ Options
  from the top of a binary tree for a CMake project it will dump
  additional information such as the cache, log files etc.
 
-``--loglevel=<error|warning|notice|status|verbose|debug|trace>``
+``--loglevel=<ERROR|WARNING|NOTICE|STATUS|VERBOSE|DEBUG|TRACE>``
  Set the log level.
 
  The :command:`message` command will only output messages of the specified
- log level or higher.  The default log level is ``status``.
+ log level or higher.  The default log level is ``STATUS``.
 
 ``--debug-trycompile``
  Do not delete the :command:`try_compile` build tree.

Source/cmakemain.cxx

@@ -96,7 +96,7 @@ static const char* cmDocumentationOptions[][2] = {
     "Generate graphviz of dependencies, see "
     "CMakeGraphVizOptions.cmake for more." },
   { "--system-information [file]", "Dump information about this system." },
-  { "--loglevel=<error|warn|notice|status|verbose|debug|trace>",
+  { "--loglevel=<ERROR|WARNING|NOTICE|STATUS|VERBOSE|DEBUG|TRACE>",
     "Set the verbosity of messages from CMake files." },
   { "--debug-trycompile",
     "Do not delete the try_compile build tree. Only "