Merge pull request #13 from mitchmindtree/master

Updated to latest rustc (switched statics to const)
fail! -> panic!
Merge pull request #14 from ebfe/fix-build-master

fail! -> panic!
Fixing "warning: lint missing_doc has been renamed to missing_docs"
Merge pull request #15 from mitchmindtree/patch-1

Fixing "warning: lint missing_doc has been renamed to missing_docs"
refactor code:
- move device and host in their own module + change their functions prototype,
remove the name from function, for example isnteed of pa::get_device_info, use pa::device::get_info
-  clean comments format to follow rust conventions
Merge pull request #16 from jeremyletang/small-refactor

code refactor
Fixed namespaced enums related error