Include lapack dependency, as the new OpenBLAS package no longer bundles LAPACK with itself.
Don't download/install patchelf if it is runnable from $PATH, and install/use it on Travis!
Add USE_SYSTEM_OPENLIBM, enable building of Julia with distribution-provided openlibm
Include openlibm packages in .travis.yml
fix the inconsistency described in #2763
this was a leftover from an older AST representation
Updates docs for publishing packages

Instructions to ensure that METADATA is up-to-date before registering a
new package.
Merge pull request #2769 from jiahao/doc-pkg-upd

Updates docs for publishing packages
Merge pull request #2767 from staticfloat/travis

Travis updates
Set: implement using a Dict{K,Nothing} instead of Dict{K,Bool}.

This is Jeff's brilliant idea: since we store Array{Nothing} using
zero space because there's only one possible Nothing value, this is
a way to use the Dict implementation for sets without wasting space
storing the array of values.
fix #2775, restore long versions of command line opts
fix mistake in git example commands
Redirect patchelf scan's stderr to /dev/null, closes #2776
Merge pull request #2777 from staticfloat/patchelfoutput

Redirect patchelf scan's stderr to /dev/null, closes #2776
fix #2780
Merge branch 'master' of github.com:JuliaLang/julia
Introduce USE_SYSTEM_RMATH to allow for system-packaged Rmath
Add in Rmath to travis config
fix #2781, ensure that the task that handles an error actually has an active handler
fix #2778, improve dataflow of finally blocks
fix #2779, chained comparisons doc
move collect() to general collections section
a couple doc fixes related to immutability