Add (React) props that control the Tweet's appearance

[ognen]

The following properties of TWTRTweetView should be exposed:

• primaryTextColor
• linkTextColor
• showBorder
• showActionButtons
• style (as tweetStyle)
• theme (light / dark)

[andianton]

• done on iOS

[ZdravkoN]

TweetStyle is not done on iOS. At the moment we will switch to Regular style instead of Compact style (Compact style hides the tweet images). This will be implemented soon.

@ognen Is that OK?