Remove metadata.json as it is generated by chef automatically

Remove metadata.json because it provides the same information as metadata.rb.
It is generated by knife/chef automatically when uploading the cookbook, so
there is not need to manage it by hand or git
correct case of README file
add recipe to install teamcity agent

Implement basic installation: download agent zip from server and extract into
directory of teamcity user.
Supports multiple agents per hosts.
agent: extract name/authorizationToken from config file

The teamcity agent writes its name and authorizationToken back into the
agent configuration file. Chef needs to extracts this information to avoid
overwritting of this information.
Name and authorizationToken are saved as node attributes. If name and
authorizationToken are already set (previous chef run or by administrator)
this information will be used (no extraction).