Do not insert chars with command key
Do not insert chars with command key

When the user selects a nonexistent command, beep instead of inserting
the key into the document.

google/xi-editor,modelorganism/xi-editor,fuchsia-mirror/third_party-xi-editor,fuchsia-mirror/third_party-xi-editor,fuchsia-mirror/third_party-xi-editor,fuchsia-mirror/third_party-xi-editor,google/xi-editor,modelorganism/xi-editor,google/xi-editor,modelorganism/xi-editor,google/xi-editor