Use atsign-simd for sum
reworked cluster manager interface
check integer truncation (#5413) and make more operators follow T+T => T (#3759)

the sysimg builds, but still need to:
  - check same-size signed<->unsigned conversion
  - make tests pass
get numbers test passing with checked integer conversions and type-stable arithmetic
make a couple things safe for checked signed<->unsigned conversion
check signed<->unsigned conversions

this would be a bit cleaner without the code in intfuncs that dispatches
on Unsigned.

signed() and unsigned() are convenient for testing bit patterns in the
test suite. for now replace with assigned() and asunsigned().

uint8(x) is convenient for moving bytes around, so it remains unchecked.
we should perhaps rename this to byte(), and either eliminate uint8()
entirely, or make it checked.
get dates tests passing with checked signed<->unsigned conversion
Merge branch 'master' of github.com:JuliaLang/julia into jb/checked_int_trunc

Conflicts:
	base/number.jl
get a few more things working with checked integer conversions
Apply custom keymaps to all prompt modes and document it.
Modify fixup-libgfortran so it works on Linux as well
Move fixup-libgfortran to `contrib/`, enable it for Linux as well as OSX
fix call to edit_transpose ("^T")
Merge pull request #8444 from rfourquet/le-Ct

fix call to edit_transpose ("^T")
Formatting: use spaces instead of tabs for indentation
Merge pull request #8448 from JuliaLang/kms/remove_tabs

Formatting: use spaces instead of tabs for indentation
Add a `versioninfo()` to default Travis
Render array objects more accurately.  Enables vectorization of 64-bit arithmetic.
Add back non-typed print methods for Float32/Float16. Fixes #8445
Merge pull request #8451 from quinnj/master

Add back non-typed print methods for Float32/Float16. Fixes #8445