nunaliit2-couch-config: Add layerDefinition schema

Issue #190
nunaliit2-js: Adjust CSS for layer selector dialog.

Issue #190
nunaliit2-js: Accepts options for layer selector in the map section of
module documents. The options available are "suppress" and
"initiallyOpened".

nunaliit2-couch-config: Update module schema to include new options.

Issue #191
Merge branch 'master' into multidb
Refactor couch-application module to ease the ability to add new design
documents.

Issue #192