Add input combination icon for multiple lock keys
Added input-combo-icon for the purpose of displaying the status of multiple lock keys; i.e., Capslock + Numlock. There are no other icons that represent multiple lock keys. The keyboardindicator applet will depend on this new input-combo-icon upon the successful merge of Kdeplasma-addons commit f377795154070101ee04390edaa8b49d3bc038d9.
