Fixed character literal encoding bug for special characters.
Added OpenDDL composition functionality

- Added constructors to structures that do not take a Decoder i.e. they are used for composing rather than parsing.
- Structure's now know about both their parent structure and the root structure to which they're attached.
- Added plenty of mutability methods to all the structures to make it easy to generate OpenDDL from structures in code.
- Added a new composition sample, which shows how custom NodeStructure sub-classes can be used to produce OpenDDL that adheres to user defined requirements.
Updated Java library manifest for 0.9.0 release.
Add Glass Echidna website link to README.