Refactoring of find motion for multi key strokes
Fix visual mode scroll bug completely!

Problem  : line('w0') & line('w$') doesn't work correctly in visual mode
Solution : Prepend <ESC> to xnoremap and modify code

Change   :
    - method of mapping
    - use softtab in plugin/EasyMotion.vim
Modify EasyMotion#User
Modify special mapping
Add helper function
Fix GetVisualStartPosition when blockwise visual
Modify mapping method
Update doc: Multi input find motion
Add prompt option
Improve command_line and move helper function
Merge branch 'feature/mjolvim-motion' into master

Conflicts:
	autoload/EasyMotion.vim
	plugin/EasyMotion.vim