Float, String, Array, Dictionary + small changes

- Float (random)
- String (*)
- Array (push, pop, shift, unshift, take)
- Dictionary (each)
Array examples, fixes

- Array examples improved and moved to Examples/Array.md
- Array (each, unique, remove)
- Array improved (range, intersection)
- Dictionary (filter, isEmpty, merge)
- Int (upTo, downTo)
- String improved (subscript, length)
Small changes + docs updated
groupBy, any, all, max, min
Better indexOf
reduceRight, implode, reduce, explode

- Array (reduceRight, implode)
- Dictionary (reduce)
- String (explode)
Update ExSwiftArrayTests.swift
groupBy, difference (Dictionary)

- Array (groupBy)
- Dictionary (groupBy, difference)
Fix
testCountBy
Xcode Framework project, new extensions

- Int (clamp, isIn)
- Array (tail)
String.length property, Functions utilities

- String.length is now a property
- ExSwift class (bind, after, once, partial)
- Int (removed after)
Docs updated
String docs
String subscript rewrote
Dictionary (union, intersection)

- Dictionary (union, intersection), fixed map & mapValue
Small changes
Array (eachRight), Int (explode)

- Array (eachRight)
- Int (explode)
Array (at, pick, improvements)
String (regex matching, ~=), NSArray -> Array