Issue 452 The installer is not configuring the hostname correctly

Closes #452

Ensure that the installer sets the hostname in output conf files

Previously, we had a post-installation action that would copy the value of raw_hostname to hostname and perform transformations conditionally if the user was using GAE
When we removed support for GAE, we broke this by removing all the post-installation actions related to the hostname variable
In this commit, raw_hostname becomes hostname, fixing the issue
This commit also adds a couple of hints to help the user fill in a value.
Users are reminded that the hostname must match their SSL certificate.

Screenshot of the Apache Tomcat Port Configuration screen when no SSL is selected: issue 451 screenshot 2

Screenshot of the Apache Tomcat Port Configuration screen when SSL is selected: issue 452 screenshot 1

What has been done to verify that this works as intended?

Build the installer, run it and verify that the output security.properties is correctly configured with whatever value is set in the Internet-visible IP address or DNS name field

Why is this the best possible solution? Were any other approaches considered?

This fixes a bug introduced when removing GAE support from the current master branch

Are there any risks to merging this code? If so, what are they?

None.

Do we need any specific form for testing your changes? If so, please attach one

No.

Does this change require updates to documentation? If so, please file an issue at https://github.com/opendatakit/docs/issues/new and include the link below.

No.

getodk / aggregate