-preview switch:
- installs pwsh-preview packages when a package manager is being used.
- uses link name pwsh-preview when tar ball install is being done
- results in preview release being available for calling manually, but does not become systemwide version
Issue #7177
Fixed#6815 by adding -allowprereleases parameter
Fixed#6405 by adding -allowprereleases parameter
Added parameters to documentation
Ready for prerelease repositories if Microsoft starts providing them
Added -skip-sudo-check for all distros
Fixed -interactivetesting should do nothing if -includeide was not used