Add Broadcast module with staged broadcast operations
Added subtypes functions, updated help, docs

* Added subtypes(T), subtypetree(T)
* Updated help(x::DataType) to print super, subtype info
* Doc fixes/updates.
fix range searchsorted methods
add percentile histogram test
integer range contains
Merge pull request #3139 from simonbyrne/sortrange

fix floating point problems in searchsorted methods for range objects
minor doc and export updates, ones() histogram test
Merge branch 'master' of github.com:JuliaLang/julia

Conflicts:
	test/statistics.jl
fix complex to negative integer power
use convert instead of int() in recent indexing fix
make Sort Ordering and Algorithm tokens instances instead of types
this eliminates many definitions and doesn't change typical uses at all
fix show() for TypeConstructor
Create containing BoundingBox given a list of BBoxes
added quadgk integration routine
fix #3142, improve === on integers
fix a pointer comparison
Add broadcast! function. Make broadcast(f) and broadcast!(f) do function wrapping.
Merge pull request #3117 from kmsquire/subtypes

Added subtypes functions, updated help, docs
small updates to subtypes() and docs
Graphics imports Base.scale (diagmm->scale renaming)
Provide broadcast_function separate from broadcast, make broadcast(f) = f()

Also provide separate broadcast!_function