Move jsNoise higher up
Refactor `Statement` family

- Reorder to match `:help :hi` list

- Move `try`, `catch`, `throw`, and `finally` to `jsException`

- Move `with`, `new`, and `in` to `jsKeyword`

- Rename `jsBranch` to `jsLabel`; remove old, unnecessary `jsLabel`

- Move `yield`, `break`, and `continue` to `jsStatement`

- Move `switch` to `jsConditional`
Refactor `jsType`

- Add `Infinity` keyword to `jsType`

- Move `const` and `var` to `jsStorageClass`

- Add `let` to `jsStorageClass`

- Link `jsNan`, `jsNull`, and `jsUndefined` to `Type` (from `Constant`)
Update global objects / builtin functions
Link `jsFloat` to `Float` (from `Number`)