Refactoring ble-edit.sh/ble-line-prompt.
Refactoring ble-edit.sh/ble-line-prompt.

* .ble-line-prompt -> ble-edit/prompt.
* _ble_cursor_prompt, _ble_line_prompt -> _ble_edit_prompt.

akinomyoga/ble.sh,akinomyoga/ble.sh,akinomyoga/ble.sh,akinomyoga/ble.sh