Added new shape mode: SHAPE_RECTANGLE
Rewritten calculateTextPosition and draw in TextDrawerImpl to be more
flexible
Return created ShowcaseView in addView in ShowcaseViews

By returning the created ShowcaseView the user can modify properties
afterwards
Manually set a rectangle to display as a showcase
Center title and text in available space
Fixed determination whether touch was outside of the cling for
rectangles
Added block all touch events feature
pointTo in ShowcaseView creates and adds hand properly
Merge branch 'bugfix-hand' into feature-text-placing-hand
Renamed getHand method to createHand and added real getHand
Considers hand boundaries while text placing
Merge branch 'bugfix-hand'
Merge branch 'feature-text-placing-hand'