Adds console logging for validation errors

[maugenst]

Hi Scott.

I recently stumbled on some swagger issues in my yaml file which was just shown as "Error in callback! Tossing to global error handler. Error: Swagger validation errors:"

So I implemented a better logging to console.error pointing the user directly to where the errors occured.
Adds console logging to console.error that points the user directly to erroneous configuration in their swagger config.

I hope this is feasible...

Thanks, Marius

[coveralls]

Coverage decreased (-0.7%) to 96.303% when pulling ce3d1a1 on maugenst:master into 2c1321b on theganyo:master.

[maugenst]

Any news on this? Any objections?

[maugenst]

Console log would be way more informative.

From:
`Error in callback! Tossing to global error handler. Error: Swagger validation errors:
at C:\github\dart.online.spielbericht\node_modules\swagger-node-runner\index.js:210:23
C:\github\dart.online.spielbericht\node_modules\swagger-node-runner\index.js:242
process.nextTick(function() { throw err; });
^

Error: Swagger validation errors:
at C:\github\dart.online.spielbericht\node_modules\swagger-node-runner\index.js:210:23
`

It would display:
`Error in callback! Tossing to global error handler. Error: Swagger validation errors:
at C:\github\dart.online.spielbericht\node_modules\swagger-node-runner\index.js:210:23
Details:
#0.: Path parameter is declared but is not defined: username in swagger config at: >paths//changePassword/user/{username}/post<
#1.: Path parameter is declared but is not defined: username in swagger config at: >paths//changePassword/user/{username}/delete<
C:\github\dart.online.spielbericht\node_modules\swagger-node-runner\index.js:247
process.nextTick(function() { throw err; });
^

Error: Swagger validation errors:
at C:\github\dart.online.spielbericht\node_modules\swagger-node-runner\index.js:210:23
`

[theganyo]

Sorry for the delay. Sounds good. Thanks for the contribution!