odML to RDF export script

[mpsonntag]

This PR adds a convenience command line script to the odML package, that searches through a given directory, converts all found odML files to the latest version and exports all odML files to the RDF format. The conversion is focused on converting as many files as possible in mixed repositories, which possibly contain unrelated XML, JSON or YAML or invalid odML files. Therefore all exceptions are ignored, the tool simply prints a report at the end of the conversion to inform about successes and failures.

After pip install, the script can be called by typing odmlexportrdf [-r] [-o OUT] SEARCHDIR with the arguments:

Arguments:
    SEARCHDIR       Directory to search for odML files.

Options:
    -o OUT          Output directory. Must exist if specified.
                    If not specified, output files will be
                    written to the current directory.
    -r              Search recursively.

The PR also updates the version to 1.4.1 to prepare for a release containing the latest RDF changes.

[coveralls]

Coverage decreased (-2.2%) to 79.545% when pulling a4a2c67 on mpsonntag:rdfExpScript into 8d455d1 on G-Node:master.

[achilleas-k]

Would it be better to have two scripts, or maybe subcommands of the same script, one for updating to newest ver and one for converting? Do we already have an upgrade script?

I also don't know if I like the name of the command. odmlexportrdf while descriptive doesn't quite sound like a nice command. Why not something like odml2rdf (in the style of dos2unix) or odmltordf (like pdftotext)?

[jgrewe]

Nice! Similar to @achilleas-k's comment I find the name a little bit cumbersome. odml2rdf or odmltordf are equally good, imho.

[mpsonntag]

pyyaml keeps failing on us...