Add button to clear current history search phrase

[nacholibre]

A minor request to add a button which clears the contents of the history search box. Currently you must manually highlight all the words and then hit the Delete key. I think a small 'X' to clear the search contents would make the UI slightly smoother.

[FrizzleFry]

+1

a minor thing but very convenient when you are mousing around

[safihre]

I will add this in Glitter (the new skin available in the beta).