support configurable path for the pazpar2 Service

the path has to be set in the variable »pazpar2Path«
before loading pz2-client.js
Readme: mark variable names as code `…`
support using Service Proxy
do not show export and KVK links by default
introduce autocomplete settings and initialise them
move CSS list-style:none settings to li

They were on ol/ul elements before as recommended by the spec,
but inside sites with existing CSS that frequently led to the site’s CSS
(which uses li) trumping our statements
Add autocomplete to the search form
add class .pz2-electronic-url to links
session loss recovery for Service Proxy

* detect Service Proxy problems by error code 100
* call service-proxy-auth URL if a 417 error occurs
* call my_oninit when Service Proxy initialisation finishes
overrideLocalisation to conveniently overwrite the built-in localisations

mainly aimed at use with TYPO3, to make localised strings configurable from there
more consistent variable names previousLink :: nextLink
let pager have »gaps« if there are too many pages
improve autocomplete integration

* start a search after selecting an item
* close autocomplete menu when submitting the search by pressing the return key without selecting an item from the menu
use choose_url from mk2.js in Service Proxy
only call jQuery UI autocomplete when it is loaded
improve Service Proxy initialisation
catch jQuery flot / Canvas exception on layouts with odd CSS

somehow the canvas can be 0 width there even though the width of the container is set

catch the exception so script execution can continue
autocomplete: actually use the selected value before starting the search
switch default language to English
include autocompleteSetupSolrSpellcheckServiceProxyXML function