Add showcompact method for vectors of Number's
Print the [] for a vector of length 0

```jl
julia> showcompact(rand(5))
[0.335052,0.678365,0.187975,0.345677,0.981752]
julia> showcompact(Float64[])
[]
```
Merge pull request #4690 from JuliaLang/db/showcompactvector

Add showcompact method for vectors of Number's
better definition of index_shape

unroll some cases of indices(), sufficient to fix #4672
this should be done the same way as index_shape, but at this time
I'm minimizing changes and possible breakage.
Use tuple for BitArray dimensions

Since we only have push! for vectors, which don't use the dims tuple,
I don't see a reason for these dimensions ever to change. This fixes
type inference for operators, which speeds up DataArray operators that
need to compute | of two BitArrays by a factor of 2+.
fix #4479, method ordering bug
Merge pull request #4700 from simonster/bitarray-tuple

Use tuple for BitArray dimensions
don't test associativity of reduce and mapreduce, since it is undefined
Merge branch 'master' of github.com:JuliaLang/julia
Some language cleanups to DISTRIBUTING.md and link it in README.md
Some more updates to DISTRIBUTING.md
Clarify warning for how to resolve ambiguous types

This warning message had me confused in two ways:
1) It wasn't clear that a remedy was suggested.
2) It wasn't clear before which definition the remedy was for.

Hopefully this clears this up for new users.
Clarify warning for how to resolve ambiguous types (take 2)

This warning message had me confused in two ways:
1) It wasn't clear that a remedy was suggested.
2) It wasn't clear before which definition the remedy was for.
3) (new) Doesn't use odd capitalization (as in previous patch).

Hopefully this clears this up for new users.
disallow : at the end of a line; fixes #4701
home(): no more user_{home,pref,documents}dir().
syntax error for non-symbol used as keyword argument
Merge branch 'master' of github.com:JuliaLang/julia
use pairwise algorithm for reduce as well as mapreduce. fixes #4702
Merge pull request #4704 from GlenHertz/patch-6

Clarify warning for how to resolve ambiguous types
home(): export portable function for finding your home directory.