Use JSDoc annotations

[adam-coster]

JSDoc annotations are being parsed, but not associated with the symbols they describe.

[adam-coster]

Changed JSDoc parsing and add support for consuming JSDocs for function definitions in 4937bba3bc603bc51d69c29864a2dec71ebcf78e

[adam-coster]

Now fully implemented for functions, just like in GameMaker, but also:

• Using @type {Type} above any variable declaration now types that variable accordingly
• Using a JSDoc comment above any variable, with or without @description, adds the comment as a description to that variable.
• Using @self above a with statement now tells Stitch to use that indicated struct as the self-scope for the statement.