TypeScript Rewrite

[elu00]

Hi all,
Here's my proof of concept for a TypeScript port. For @nitin42 's proposed port to Flow, see #155
Here's what I've done so far:

• Updated all module imports/exports to TypeScript syntax.
• Fixed almost all TypeScript compiler errors directly from the port
• Refactored the Node class to MathNode
• All temporary objects ported to classes with static methods.
• Added static typings for mathjs functions from DefinitelyTyped.
• Added static typing for most node paramters

To Do:

• Add tsconfig.json for automated compilation/syntax changing.
• Create library declaration file
• Add type annotations to the rest of the variables and parameters.
• Fix Creator.ts
  I'd welcome any feedback or comments!
  I'll also try to finish up the to-do list and the rest of the port within the next several weeks.
  EDIT: Actually, given what I've learned so far going through the codebase and the all the other feature's I've learned about, I'll probably actually be completely rebasing and re-doing this port if we decide to go the way of TS instead of flow

[kungfooman]

What a messy PR, just add JSDoc with a jsconfig.json for full Intellisense + typing:

{
  "compilerOptions": {
    "checkJs": true,
    "strict": true
  }
}