ksLookup changes

- allow lookupBySpec by argument in ksLookup
- "kdb get" cli accepts cascading names
- ksLookupBySpec should now compile using mingw
kslookup

- move helpers to lookup direct above kslookup
- refactor kslookup (move cascading code)
add creating lookup

lets user avoid very common pattern:
ksLookup()
if (!found)
{
	ksDup();
	ksAppendKey();
}
make different lookups private

- refactor to elektraLookupLinear/BinarySearch
JNA now allows to read from KDB
add listAllAvailablePlugins and kdb list

allow to list all available plugins