fixing bug in Enable.wx_backend's handling of key events where Ctrl + a special key (e.g. those in the keymap) was not being handled correctly.  this bug was introduced in changeset 13372.
fixing bug in Enable.wx_backend's handling of key events where Ctrl + a special key (e.g. those in the keymap) was not being handled correctly.  this bug was introduced in changeset 13372.

tommy-u/enable,tommy-u/enable,tommy-u/enable,tommy-u/enable