Merge pull request #17 from csherratt/master

added option type for local work size
add device.computeUnits() to return max number of compute units
add managed_boxes flag
Updating with Rust IO changes.
added option type for local work size
Move some of the memory operations to the command queue to match OpenCL's API.
Moved some of the structures to public
updated test.rs to work with hl changes
Added a type binding to CLBuffer
fixed read working with an immutable vector
Added &OpenCL::hl::Event support.
fixed indentation
added vector read function to command queue
remove vector type
Remove CommandContext
cleanup pt1
added new memory api