Silence jshint warnings

This branch silences many of the jshint warnings that arise from ordinary use of jsiohint.

After the source code has been processed by the jsio transformer, jsiohint runs a shimming pass, transforming calls to `jsio` into top-level variable declarations.

It recognizes calls in any of the following forms.
````
jsio("import ui.View;");
jsio("import ui.View as View;");
jsio("from ui.filter import MultiplyFilter;");
jsio("import src.lib.CoolTool.Widget as CoolTool.Widget;");
````

The shimming pass transforms these lines into the following form.
````
var CoolTool = jsio("import src.lib.CoolTool.Widget as CoolTool.Widget;");
````

Additionally, it prepends a line declaring the globals provided by devkit, `jsio`, `merge`, `Class`, and `bind`.

Finally, it takes the data output by jshint and decrements all the line numbers to compensate for the shim line introduced by the preprocessor.