commit 650cee2

Improve documentation for -n and -I switch.

 1@@ -52,8 +52,9 @@
 2   Enable key repeat for joypad emulation.
 3 
 4 -n
 5-  Disable GUI. This switch is required in order to read stdin; without it,
 6-  stdin cannot be read (although command-line arguments still work).
 7+  Disable GUI. Either this switch or -I is required in order to read stdin.
 8+  If neither -n nor -I is specified, then stdin cannot be read (although
 9+  command-line arguments can still be read).
10 
11 -p #
12   Select the palette. Valid palette numbers are 0 to 7, where 7 is the