Add Install_Log to record a comment line in the log
Allow an arbitrary line of text to be added to the current installer log so that (for example) the origin of a set of changes can be demarked like "Installer script provided with MyApp".
The command operates similarly to *Echo in that
- system variables are expanded by GSRead
- up to 255 words may be present
plus
- any unprintable control characters are substituted for a dot
- words are wrapped at 80 characters