added isopen(io) for IOStream and IOBuffer
fix apparent typo: File adds a readbytes method, not readall
add isopen(::File)
fix merge conflict
add more isreadable/iswriteable/isreadonly functions
Revert byte order IO changes [dba7023bf1, dccba38814].

Apologies, Simon. This API change just wasn't thoroughly enough
worked out. It causes tons of method ambiguities with existing
packages, which is generally a danger sign that something may be
rotten in Denmark. In general, having trailing objects as a way
of modifying behavior seems sketchy. The sorting API used to do
this but has been reworked to use keywords instead.

Revert "add additional tests for scalars and floats"
This reverts commit dba7023bf16947851ffd29d1021a8b48b403890c.

Revert "Added ByteOrder type for reading integers, floats, complex, arrays, and bitarrays"
This reverts commit dccba38814e09df7e4d8e101d8993ff235fcdb17.

Conflicts:
	doc/helpdb.jl
on OS X, prioritize usage of libraries in JULIAHOME/../lib and JULIAHOME/../lib/julia
fix #3821
Fix #3867
Merge pull request #3871 from stevengj/isopen

added isopen(io) for IOStream, IOBuffer, and File
Merge pull request #3872 from stevengj/readwritable

add more isreadable/iswriteable/isreadonly functions