Annotate parse tree with names of tengwar and tehtar when available

[kriskowal]

I’ve committed names.js as a reference. The names of the letters depends on the mode and the language of their use. With simplifying assumptions, the names of the letters as known in Gondor might be applied for the mode for General Use, and the Quenya names for the Classical mode. Even with these simplifying assumptions, some tengwar have different names based on the paired tehtar. The letter names will have to be carried by annotations as generated by the parser.