Update Windows Agent Installer to 1.7 and WinSW to 2.0.2 (#2765)

### WinSW changes

The update includes many fixes and improvements, the full list is provided in the [WinSW changelog](https://github.com/kohsuke/winsw/blob/master/CHANGELOG.md). There are several issues referenced in Jenkins bugtracker:

* [JENKINS-22692](https://issues.jenkins-ci.org/browse/JENKINS-22692) - Connection reset issues when WinSW gets terminated due to the system shutdown
* [JENKINS-23487](https://issues.jenkins-ci.org/browse/JENKINS-23487)- Support of shared directories in WinSW
* [JENKINS-39231](https://issues.jenkins-ci.org/browse/JENKINS-39231) - Enable Runaway Process Killer by default
* [JENKINS-39237](https://issues.jenkins-ci.org/browse/JENKINS-39237) - Auto-upgrade of JNLP agent versions on the slaves

### Windows Agent Installer changes

* Adapt the default configurations to pick fixes above
* Slave => Agent renaming where possible

### Jenkins core changes

* Modify the configuration template, reference advanced options
* Enable Runaway Process Killer by default

* Update Windows Agent Installer to 1.7

* Remove the obsolete jenkins-slave.xml file from the core.

Now it is within windows-slave-installer

* Use the deployed Snapshot for CI

* Pick the release version of windows-slave-installer-1.7