Continue to generate docs, even with Parse error

[jongunter]

In addition to the defect mentioned here: #92 ...it would be nice if gulp-ngdocs could have a setting flag that lets it continue parsing and generating documentation, even with an error.

I'm currently working on a project with 30ish angular modules and over 100 components. It frustrates me that if one component has broken documentation, we lose our documentation for everything until the developer in question fixes their ngdoc formatting.

Bonus points if this feature can display a message on the corresponding component's documentation page saying "There are syntax errors here" or something.