Add banner style & demo code
SIToastViewStyleDefault change to SIToastViewStyleBanner; Implement style setter method; Change define to method
Merge pull request #1 from vitoziv/master

Add banner style & demo code
Merge commit 'b3cc90705c029dfeea7a3d3d846217d63158cf38' into develop

Conflicts:
	SIToastView/SIToastView.h
	SIToastView/SIToastView.m
	SIToastViewExample/SIToastViewExample/ViewController.m