Reimplement color processing

Summary:
**Problem:**

As I was trying to document what color formats we supported, I realized that our current implementation based on the open source project tinycolor supported some crazy things. A few examples that were all valid:

```
tinycolor('abc')
tinycolor(' #abc ')
tinycolor('##abc')
tinycolor('rgb 255 0 0')
tinycolor('RGBA(0, 1, 2)')
tinycolor('rgb (0, 1, 2)')
tinycolor('hsv(0, 1, 2)')
tinycolor({r: 10, g: 10, b: 10})
tinycolor('hsl(1%, 2, 3)')
tinycolor('rgb(1.0, 2.0, 3.0)')
tinycolor('rgb(1%, 2%, 3%)')
```

The integrations of tinycolor were also really bad. processColor added "support" for pure numbers and an array of colors!?? ColorPropTypes did some crazy trim().toString() and repeated a bad error message twice.

**Solution:**

While iteratively cleaning the file, I eventually ended up reimplementing it entierly. Major changes are:
- The API is now dead simple: returns null if it doesn't parse or returns the int32 representation of the color
- Stricter parsing of at
Closes https://github.com/facebook/react-native/pull/5529

Reviewed By: svcscm

Differential Revision: D2872015

Pulled By: nicklockwood

fb-gh-sync-id: df78244eefce6cf8e8ed2ea51f58d6b232de16f9

Libraries/ReactIOS/requireNativeComponent.js

@@ -106,12 +106,16 @@ var TypeToDifferMap = {
   // (not yet implemented)
 };
 
+function processColorArray(colors: []): [] {
+  return colors && colors.map(processColor);
+}
+
 var TypeToProcessorMap = {
   // iOS Types
   CGColor: processColor,
-  CGColorArray: processColor,
+  CGColorArray: processColorArray,
   UIColor: processColor,
-  UIColorArray: processColor,
+  UIColorArray: processColorArray,
   CGImage: resolveAssetSource,
   UIImage: resolveAssetSource,
   RCTImageSource: resolveAssetSource,