fix issue #41 Characters out of order on android web browsers

Android browser has a bug in setSelectionRange function as described in
http://code.google.com/p/android/issues/detail?id=15245
http://stackoverflow.com/questions/4861698/focus-textarea-with-caret-after-text-in-android-browser
http://stackoverflow.com/questions/6103476/android-keyboard-and-javascript

I used a workaround suggested in one of the links. Since android browser
cannot be reliably detected, we just add setting for it (for example
tablet browser with mobile mode switched off).