added opacity slider functionality

Signed-off-by: Jared Allen <jared@redcact.us>
removed stray NSLog

Signed-off-by: Jared Allen <jared@redcact.us>
- centered opacity grid in loupe

- renders based on number of columns instead of arbitrary pixel width

Signed-off-by: Jared Allen <jared@redcact.us>
Merge branch 'opacity-slider' of https://github.com/jallen/RSColorPicker into jallen-opacity-slider

Conflicts:
	RSColorPicker.xcodeproj/project.pbxproj
	RSColorPicker/ColorPickerClasses/RSColorPickerView.m
	RSColorPicker/RSColorPickerAppDelegate.h
	RSColorPicker/RSColorPickerAppDelegate.m
Show both brightness and opacity slider
Update PodSpec
Update README
Cleanup loupe changes
Merge branch 'jallen-opacity-slider'