Extracts directory dependent import operations to a new method

The directory dependent parts of the initialize method in
experiment_parser.rb were extracted into another method.
This way, an alternative method for importing from zip file can
easily be added.

Refs #8
Implements parseFromZipFile method. UNTESTED

Refs #8
Fixes some path confusion.

A path can be a relative or an absolute path.
Adds import_done to seeds
Fixes spelling mistake
Improves controller for import

Changes order of if statements to allow import using file stored on the server
after selecting a file to upload.
Fixes experiment new form to allow upload
Merge branch 'feature8'