Loose end: ints(), longs()

[Brian Goetz]

Another loose end is a method to generate "all" ints / longs (which are 
sugar for ranges 0..MAX_VALUE.)  These show up in pedagogical examples 
all the time:

   ints().filter(i -> isPrime(i)).limit(100)

The logical place for them is:

   IntStream.ints()
   LongStream.longs()

but some have raised concern that this might be confusing because we 
have an instance method on IntStream called "longs()" which widens the 
elements from int to long.  While this isn't fatal, it might be confusing.

Perhaps it would be better to rename these conversion methods:

   IntStream: longs(), doubles(), boxed()
   LongStream: doubles(), boxed()
   DoubleStream: boxed()

to asInts(), asLongs(), and asBoxed()?

In retrospect, these seem better names anyway.  And they also eliminate 
the conflict above.