Convenience methods to add

[sanmai]

• prepend(iterable) #106
• append(iterable), push(...$vector) #107
• Add merge() #103
• last(callable $selector = null, $default = null),
• first(callable $selector = null, $default = null), pull()
• flip (from array_flip) Add flip() #100
• nth(int $step, int $offset = 0)
• chunk (from array_chunk) #109
• skipUntil, skipWhile, takeWhile, takeUntil #128
• slice($offset, $length = null, $preserve_keys = false) #105
• combine, keysFrom, valuesFrom
• splice($offset, $length = null, $replacement = []) #104
• max, min Add min(), max() #99
• uniq($keyfn)
• each() #136
• dedup()
• bloomFilter()