Support initialize form nib file
Merge pull request #3 from nowsprinting/initFromNib

Support initialize from nib file
added support for overriding default segment insets, supports disabling segment background gradients
updated README with additional customization options
updated demo code
integrated bug fixes/additions from @nowsprinting, fixed bugs with showGradient
Merge branch 'master' of git://github.com/u10int/URBSegmentedControl into u10int-master

Conflicts:
	URBSegmentedControl.m