fix default ncv and errors/warnings
Mention `@` sign collisions

This happens a lot in discussions. Mentioning it might cut down on the amount of times we remind people.
Sometimes, due to linking funniness, libgfortran/libgcc can look like it's coming from multiple places at once.
updated stdlib docs
Merge pull request #7607 from Jutho/jh/eigs-defaultncv

eigs: fix default ncv and errors/warnings
Merge pull request #7591 from sjkelly/patch-2

Mention `@` sign collisions
fix an annoying random failure in test/sparse.jl

ref #6854

also fix an old mistake of mine in the test for #5853 where the loop should be over the dense version
test/socket.jl: use a random port to avoid port conflicts.
Export sumabs and sumabs2

Fixes #7032
Merge pull request #7612 from JuliaLang/sjk/sumabs

Export sumabs and sumabs2
fixed commit
Merge branch 'master' of git://github.com/JuliaLang/julia
 remove typo
Merge pull request #7614 from mcprentiss/master

Fixing redirected links in documentation. Rebase and fixed from #7606