Merge pull request #8 from raphaelm/master

update with latest commits from raphaelm
Basic implementation of SRU (#163)
First testing catalogue is the GBV catalogue, we need to put the
supported search parameters in the JSON file, because they can be
different on each library. Also, it currently only supports a small set
of media properties, not all the ones supported by the MODS XML format.
Extended SRU:
multiple search parameters (defined in JSON)
right encoding (UTF-8)
convert ISBN13 to ISBN10 to get cover image from Amazon
SRU: added getResultById() and share URLs
Merge pull request #207 from johan12345/master

SRU implementation (#163)