[apitools] no API error reported with missing bin folder

[laeubi]

If the output folder is missing, it could happen that API tools report no error but simply logs an error then

[ERROR] Error logged from API Tools Core:
org.eclipse.core.internal.resources.ResourceException: Resource '/bundle1/bin' does not exist.
at org.eclipse.core.internal.resources.Resource.checkExists (Resource.java:367)
at org.eclipse.core.internal.resources.Resource.checkAccessible (Resource.java:241)
at org.eclipse.core.internal.resources.Resource.accept (Resource.java:100)
at org.eclipse.core.internal.resources.Resource.accept (Resource.java:92)
at org.eclipse.pde.api.tools.internal.model.ProjectTypeContainer.collectPackageNames (ProjectTypeContainer.java:167)
at org.eclipse.pde.api.tools.internal.model.ProjectTypeContainer.getPackageNames (ProjectTypeContainer.java:153)
at org.eclipse.pde.api.tools.internal.model.AbstractApiTypeContainer.getPackageNames (AbstractApiTypeContainer.java:166)
at org.eclipse.pde.api.tools.internal.model.ApiBaseline.resolvePackage0 (ApiBaseline.java:622)
at org.eclipse.pde.api.tools.internal.model.ApiBaseline.resolvePackage (ApiBaseline.java:551)
at org.eclipse.pde.api.tools.internal.provisional.comparator.ApiComparator$2.visit (ApiComparator.java:685)
at org.eclipse.pde.api.tools.internal.model.ArchiveApiTypeContainer.accept (ArchiveApiTypeContainer.java:190)
at org.eclipse.pde.api.tools.internal.provisional.comparator.ApiComparator.internalCompare (ApiComparator.java:655)
at org.eclipse.pde.api.tools.internal.provisional.comparator.ApiComparator.compare (ApiComparator.java:289)
at org.eclipse.pde.api.tools.internal.provisional.comparator.ApiComparator.compare (ApiComparator.java:315)
at org.eclipse.pde.api.tools.internal.builder.BaseApiAnalyzer.checkCompatibility (BaseApiAnalyzer.java:1509)
at org.eclipse.pde.api.tools.internal.builder.BaseApiAnalyzer.analyzeComponent (BaseApiAnalyzer.java:268)