Fix qr multiplication
Merge pull request #4657 from JuliaLang/anj/qr

Fix qr multiplication
Minor language edits to the help text for qrfact, qrpfact, cholpfact.
doc/maual: update list of vectorized ops
doc/manual: add special functions to builtin list

Also moved some functions to the new section, e.g. erf, gamma
doc/manual: small fix in "parametric abstract types"
Resize image on disk, for #4666
docs: remove mention of `randf` which doesn't exist.

Use `rand(Float32,dims...)` instead.
Merge branch 'master' of github.com:JuliaLang/julia
Removed branch info from splash screen on tagged commits

When checking out a tagged commit, git puts you in a detatched state
where you are not currently on a branch. This looks a bit stupid when
compilling official releases that proclames that they are from
(nobranch) or (detatched from .....). This commit adds a flag to
BUILD_INFO to tell if the current commit is tagged, and ignores branch
information on the splach screen if the commit is tagged.

Fixes #4661
Show info on last origin/master commit if on a fork