Adding more customization options

[nathanfallet]

In this pull request:

• I added a parameter to control torch light: fixes #50
• I added a parameter to present gallery (to import a code): fixes #51
• I added a parameter to choose video capture device: fixes #22

[nathanfallet]

@twostraws The pull request is ready, and should fix #50, #51 and #22 😄 Feel free to review it and merge it when you have time to

[twostraws]

Hi Nathan! Thank you for your contribution – it looks great! Can you confirm this doesn't break compatibility with the existing 2.0.0 release?

[nathanfallet]

@twostraws I can confirm it does not break anything, as I only added optional arguments with default values.

[twostraws]

Thank you!