changing border color of active window to blue and window border to 2
Summary: The border of active window was change to blue t avoid confusion of title bars. Also border was made thicker so it's easier to grab it.
Test Plan: check color and broser sieze of active window
Reviewers: wxl, tsimonq2
Reviewed By: wxl, tsimonq2
Differential Revision: https://phab.lubuntu.me/D18