nunaliit2-multimedia: Make changes to ImageMagick processor for versions
6.5 and prior. Accepts command patterns provided in the configuration
files. By switching to default command patterns, the [0] image index is
provided.

nunaliit2-js: In couchShow, when a thumbnail is not available for an
unrecognizable file class, provide a generic "file" icon.

Issue #133
Merge branch 'master' of https://github.com/GCRC/nunaliit.git
nunaliit2-couch-application: In validate_doc_update function, do not use
regular expression literals. Instead, use explicit RegExp constructor.
This is to avoid bugs on versions of CouchDb where regexp literals are
not supported.

Issue #138