Improving server side error handling

[slatkovic]

In a case of an error on the server side, the next middleware in chain is called without logging the error. In some cases the rendering logic silently fails and it's hard to debug rendering issues. An example would be rendering a template from an existing error middleware.

Suggested improvement: Adding a debug statement in the catch block.

[samsel]

@slatkovic are you suggesting to add something like debuglog? A PR would be awesome. if not, will address this as soon as we get done with making react-engine compatible with react-router 1.x