Removed Container interface. Renamed Location to IDComponent. Created a new type Location, which embeds IDComponent. Cleaned up h5p.go
Made Datatype a Location.
Merged h5l.go with h5i.go since there wasn't any code in h5l.go
Add Type() method for IDComponent.
Renamed IDComponent to Identifier, in deference to the C API. Made Table a Location.
Add Id() method to Identifier.

Fixes the build.
h5a: migrate to Identifier
Refactored h5t.go. Datatype is not longer required when calling Dataset Read or Write.
Merge pull request #12 from sbinet/dev/merge-back-kisielk+echlebek-changes

Dev/merge back kisielk+echlebek changes