Update example project

[skywinder]

Add ability to change animation style from the project.

[Boris-Em]

Hi @skywinder, thank you so much for your work on BEMSimpleLineGraph!
This PR looks good overall.
I just have a quick question though, why is BEMDefaultAnimationTime publicly declared (in BEMSimpleLineGraphView.h instead of the .m)?
Also, I think that it would be better if in the sample project, Bezier curves would be used when the app is launched for the first time.

[skywinder]

@Boris-Em Yes, both remarks are reasonable. Fixed!

[skywinder]

Also I fix names in segment control in last 2 commits.

[Sam-Spencer]

Commit 20d9253 lays the groundwork for future customizations of the graph directly from the sample project. Although the feature is not fully implemented yet, this is the direction we are headed (rather than cluttering the Refresh Settings area).

Additionally, commit 9b5b787 adds IBDesignable capabilities to BEMSimpleLineGraph. Now you can alter the appearance of the graph directly from Interface Builder.

Thank you for the Pull Request!

[skywinder]

It seems, that this PR is not pertinent anymore. Thanks for your improvements! 👍