Add developer documentation for :meta expressions
Merge pull request #8459 from JuliaLang/teh/docmeta

Add developer documentation for :meta expressions
JITMemoryManager header file removed from llvm-svn.

Fix https://github.com/JuliaLang/julia/issues/8460
Merge pull request #8471 from crayxt/patch-8

JITMemoryManager header file removed from llvm-svn.
Correct documentation for least squres \ and make documentation for elementwise operations more precise.
rename None to Union(), and Nothing to Void. fixes #8423

I also use Bottom === Union() some places in Base.

remove a couple redundant show methods that snuck in somehow.
remove some missed 0.3 deprecations in cconvert.
Slight cleanup of staged function code
Merge branch 'master' of github.com:JuliaLang/julia
fix #8464
Merge pull request #8474 from JuliaLang/anj/doc

Correct documentation for least squres \ and make documentation for elementwise operations more precise.
fix #8473
Merge pull request #8477 from ivarne/edit-jl

fix #8473
Add fallbacks for expression resolution (fix #8478)
Fix #8468. Respect last_idx in prefix searching.