List functions to add to web service

[AlexanderPico]

Here are the functions we're missing:

• no equivalent of AttributeMapper?.getAttributeSet
• no equivalent of AttributeMapper?.getAttributes (Xref) or getAttributes(Set<Xref>)
• no equivalent of mapID (Set<Xref>) (using POST)
• no equivalent of isFreeSearchSupported
• distinguish srcDataSources and tgtDataSources
• no equivalent of isMappingSupported
• backPageText is obsolete, may be removed

While we're changing this, I have another proposal: The ordering of arguments seems weird / inconsistent to me. I think we can go for a "action/params" pattern instead of "(model|search)/params/action". Or I don't understand really where Isaac was going with this, maybe you can ask him? But I think this might be clearer:

/xrefs/{SYSTEM}/{ID} (with POST version for multiple results)
/attributes/{SYSTEM}/{ID} (with POST version for multiple results)
/search/{QUERY}[&limit={LIMIT}]
/attributeSearch/{QUERY}[&limit={LIMIT}][&attrName={ATTRNAME}]
/properties
/isFreeSearchSupported
/targetDataSources
/sourceDataSources
/isMappingSupported/{SRC-SYSTEM}/{DEST-SYSTEM}
/attributeSet