MyScroller_for_android per Myx_CJK

Clarification. this extension is heavily based on fox scoller extension. Modification has been made to make the Fox-scroller compatible with Firefox For android for my own personal use. (I formerly never planned to upload it to add-on store and intended to use the add-on locally, but new android firefox rules requires the add-on to be submitted to their store for it to work so there we are)