Don't assume default project settings

When trying to run eclipse on a build that has a non-standard project, I get the following errors:

[error] Could not create Eclipse project files:
[error] Undefined setting 'name'!
[error] Undefined setting 'unmanaged-source-directories'!
[error] Undefined setting 'class-directory'!
[error] 
[error] 
[error] 
[error] Undefined setting 'unmanaged-source-directories'!
[error] Undefined setting 'class-directory'!
[error] 
[error] 
[error] 
[error] Undefined task 'external-dependency-classpath' for 'dist'!
[error] Undefined task 'update' for 'dist'!
[error] Undefined task 'update-classifiers' for 'dist'!
[error] Undefined task 'external-dependency-classpath' for 'dist'!
[error] Undefined task 'update' for 'dist'!
[error] Undefined task 'update-classifiers' for 'dist'!

This project is not meant to have update, external-dependency-classpath or even name. It doesn't compile class files. As such, it doesn't need eclipse settings files, it can just be ignored. It'd be ideal if the plugin allowed such projects to exist without negating the generation of settings for others.

Start with the eclipse command and reproduce the reported undefined settings and tasks for a non-standard project. Trace how Eclipse project definitions are generated, then verify that projects without name, class files, or the listed tasks are ignored while settings for other projects are still generated.