Work on the NSIS installer (#2558)
Work on the NSIS installer (#2558)

- enable to choose the app directory too, so we write foxxes into the proper locations
 - strip out more fuzz about global installation and services
 - add a custom uninstaller page showing which directories we intend to delete
 - more cleanup
joerg84/arangodb,arangodb/arangodb,arangodb/arangodb,arangodb/arangodb,joerg84/arangodb,fceller/arangodb,fceller/arangodb,wiltonlazary/arangodb,graetzer/arangodb,graetzer/arangodb,wiltonlazary/arangodb,hkernbach/arangodb,joerg84/arangodb,fceller/arangodb,arangodb/arangodb,hkernbach/arangodb,hkernbach/arangodb,Simran-B/arangodb,fceller/arangodb,graetzer/arangodb,arangodb/arangodb,hkernbach/arangodb,wiltonlazary/arangodb,graetzer/arangodb,Simran-B/arangodb,graetzer/arangodb,fceller/arangodb,fceller/arangodb,Simran-B/arangodb,wiltonlazary/arangodb,wiltonlazary/arangodb,graetzer/arangodb,joerg84/arangodb,joerg84/arangodb,Simran-B/arangodb,arangodb/arangodb,fceller/arangodb,joerg84/arangodb,hkernbach/arangodb,graetzer/arangodb,graetzer/arangodb,fceller/arangodb,graetzer/arangodb,Simran-B/arangodb,graetzer/arangodb,hkernbach/arangodb,wiltonlazary/arangodb,graetzer/arangodb,fceller/arangodb,graetzer/arangodb,hkernbach/arangodb,wiltonlazary/arangodb,joerg84/arangodb,Simran-B/arangodb,joerg84/arangodb,joerg84/arangodb,Simran-B/arangodb,hkernbach/arangodb,hkernbach/arangodb,joerg84/arangodb,fceller/arangodb,Simran-B/arangodb,hkernbach/arangodb,hkernbach/arangodb,hkernbach/arangodb,joerg84/arangodb,arangodb/arangodb,Simran-B/arangodb,joerg84/arangodb,graetzer/arangodb,wiltonlazary/arangodb,Simran-B/arangodb,graetzer/arangodb,hkernbach/arangodb,arangodb/arangodb,joerg84/arangodb,hkernbach/arangodb,joerg84/arangodb