sizehint for Sets now returns the given Set

It previously returned the Dict as-per:

    https://groups.google.com/forum/#!topic/julia-users/COdDQwrgKQQ
Consistent formatting as per feedback from @ivarne
Merge pull request #6883 from ninjin/nin/set_sizehint

sizehint for Sets now returns the given Set
Fix multimedia display in REPL code
initializing default id to 1
Merge pull request #6889 from amitmurthy/amitm/id

initializing default id to 1
use size in hashing AbstractArrays

make hashing test stricter to also check for collisions. there shouldn't be
any for these simple cases.
Merge branch 'master' of github.com:JuliaLang/julia
Typo.

I must be the first person to use this generic :-)
Merge pull request #6890 from JuliaLang/db/syr

Correct a typo in BLAS.syr!
fix missing argument in print_help_entries
Fix typo in BLAS level 3 perf tests and make tiny large enough to call BLAS
Merge pull request #6892 from JuliaLang/anj/perf

Fix typo in BLAS level 3 perf tests and make tiny large enough to call BLAS
wip: sparse csr
wip: sparse csr
wip: sparse csr