Windows Installer does not use version specific jira home directory

If you use the windows installer to install a new version of JIRA and you already have a previous version of JIRA, the same home directory is used.

This has a number of knock-on effects. Firstly, it wrecks the contents of the home directory for the previous version. Secondly, the new JIRA may fail to start, for example if the JIRA home directory is locked.

The installer was deliberately made to install JIRA in a version specific location and to check that system singletons like the network port are checked to see whether they are available so that the upgrade instructions (install alongside then test and cut over) would work with the installer.