Featurehistory

I made additions to the res/values/strings file adding two strings for the history preference xml. 
I made additions to the res/xml/pref file adding a checkbox preference for the turning off history.
I made addition to the PreferenceActivity file adding a constant string variable for the history.
I made addition to the CaptureActivity file adding an if statement to check history preference before storing history after livescan. 

I made these additions using a text editor and also have the patch saved if emailing a patch would be better. 
Indentation and spacing is off here.