Simplify install process a bit

AndServer/Makefile:
* Remove DES3 password on server.key and client.key, so you don't have to enter a password multiple times when generating certificates.
* Add a new target "certinstall" that moves server.pem and client.pem to /etc/andserver/ directory.

Files
* Add AndServer/Cert/.gitignore to make the Cert directory part of repository
* Updated .gitignore files to stop some files from ending up in repository

AndServer/andserver.conf.example
* Change paths to use default cert and key install dirs (/etc/andserver/)
* Fixed some errors in the "client-certificate-file" part

README.md
* Updated to reflect the changes

Note: This is the first time i use GitHub and Git.