Fixed case behaviour

* case no properly handles -h and --help flags, i.e. treats it as
  pattern
* fixed case escaping:
The following expressions now work correctly:
switch '*'
  echo '*'
  echo Match any string
end
switch '*'
  echo '\*'
  echo Match asterix
end
switch '\\'
  echo '\\\\'
  echo Match slash
end

The same for '?' sign

share/functions/funced.fish

@@ -4,7 +4,7 @@ function funced --description 'Edit function definition'
     set -l funcname
     while set -q argv[1]
         switch $argv[1]
-			case '---long impossible to match line, because case respects -h option' -h --help
+			case -h --help
 				__fish_print_help funced
 				return 0