Merge pull request #26 from itdaniher/master

s/rt::io/io/
Updating to latest Rust.
Fix subtle bug != should have been |=.
added create_compute_context_prefer
add drop for Array2D/3D
Merge pull request #27 from csherratt/master

Miscellaneous changes
Adjusting to latest linking changes
Updating to latest rust.
Minimal rustdocs.
Updating to latest Rust.
Added another docstring.
Add pkgid for rustdoc.