Adds documentation for neo4j-installer and updates it for neo4j

* The docs on neo4j-installer goes into the zip packages as text files in the documentation dir, but not into the deb packages.
* The neo4j-installer manpage is visible in the manual as well.
* I removed the neo4j manpage from the deb packages as the command doesn't get installed on the system anyhow.
* Tells Linux users to use prebuilt installation packages if they can.
* Updated windows information to be in sync with the installation guide.