Add stream-based parser and serializer (like MongoDB Java Driver)

[fluidsonic]

• Decide whether to treat map keys as values or whether to add special token type and readKey() method
• Parse double directly without temporary string.
• Add tests for character indexes in exception messages.
• Add tests for keypaths in exception messages.
• Should we wrap IOException, InterruptedException (all Exceptions?) in JSONException?
• Serialize numbers without temporary string.
• Improve performance by using Input/OutputStream directly.
• Support Appendable.
• Support Readable.
• Support reading & writing Byte and Short.
• Support reading & writing Char.
• Allow peeking whether next number has decimal point or exponent in JSONReader.
• Properly close readers & writers in tests.
• Add overloads for readString and writeString which operate on CharArray and alike.
• Add options (e.g. handling of unserializable values, max nesting, max number length, max string length)
• Add dedicated tests for TextInput.