Improve copy in uninstaller - including add explanation to user that not all files will be removed

1. Change application title from "...Uninstall" to "...Uninstaller"
2. Change welcome screen title from "...Uninstall" to "...Uninstaller"
3. Change main body text as not all components are removed e.g. the home directory. This needs to be explained. Perhaps change "Are you..." to "This will remove the evalaution version of Confluence, but not your Confluence home directory and its contents."
4. Change text "Click Next to continue or Cancel to exit Setup." to "Click Next to continue or Cancel to exit the uninstaller."