add hist2d function (2-dimensional histogram)
`sum` method for AbstractArray{BigFloat}
`sum` method for AbstractArray{BigInt}
More efficient +,*,$,|,& methods for BigTypes

If the above functions are called with up to five arguments BigType
, the only allocation that will happen is of the return variable,
without any other temp variables.

This happens with +,* for BigFloats, and with +,*,$,|,& for BigInts.
Merge pull request #3065 from andrioni/master

Add `sum` methods for BigInts and BigFloats
fix #3061, partitions() of 0 or 1 elements
Merge branch 'master' of github.com:JuliaLang/julia
Update logdet. Close #3070.
Update .travis.yml configuration in the manual.
Use Number instead of Integer in some linalg operations
Merge pull request #3052 from daviddelaat/linalgnumber

RFC: Use Number instead of Integer in some linalg operations
=== fallback can now replace == definitions for basic integer types
a couple other equality-related fixes:
  !isequal(-0.0f0, 0.0)
  signbit() for BigFloat, make BigFloat isequal() work
  == and isequal for Ranges

clean up fpiseq and fpislt intrinsics a bit
fix conversion of -0.0 to Uint
fix #3018 and update windows build instructions (closes #3049) to avoid gcc/openblas compile bugs
fix corner case of iround(prevfloat(0.5))
Merge branch 'master' of github.com:JuliaLang/julia
Update README.windows.md formatting
WINDOWS: fix win32 build and tests
remove a couple more redundant intrinsics
a bit more about isequal() and floats in the manual
Merge pull request #3026 from JuliaLang/jn/linalg_additions

hist2 implementations