Add engine cycling keymap
Implement next_engine() in ibus-agent
Implement ibus_cycle SublimeText command
Ignore *.pyc files
Translate README to English
Try to commit characters unhandled by IBus engine
Implement ibus_forward_key_event_cb

Currently, it only processes backspace events. A necessary feature
required by ibus-bogo.
Fix \\ character in the English translation.