Wizard for creating a resource

[arildm]

The corpus overview screen is overwhelming (#68) and the help/error messages do not always very clearly show what action needs to be taken. It's a good fit for a wizard, i.e. a series of short forms.

Add a button "Create resource" When user clicks it:

Task for user	App will then...
1. (Later: Choose resource type. Now there's only corpora.)	Create corpus
2. Enter a name and upload text files	Upload config, upload sources, determine format (#66)
3. Depending on format, specify other config options	Upload config
4. Arrive to overview, where corpus is now ready for annotation