Toggle style enhancements

[lucafalasco]

Would be super cool to have 5 possible inputs to pass:

• width
• height
• default background color
• active background color
• toggle color

So that we can do easily this type of customization. The toggle size and its two positions (on/off) should then be dynamically calculated.

Nit on/off labels

Originally posted by @aminalhazwani in #49 (comment)

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Another point: would be maybe useful to add a LabeledToggle too.

Originally posted by @caesarsol in #49 (comment)