1. Add optional argument localDev to the primary powershell script to allow using a locally modified version of craft. Intended to facilitate development.
2. Correct some strings using \ which caused python to fail when loading the script.
I'm not sure how they lasted so long as they are. Python 3.7 on Win10 produced an error when
trying to load them.
3. Various typos in messages to user corrected. Some messages reworded for clarity.
4. The search for pre-release versions of MSVS is automatic, occurring only if the regular
search finds nothing. A note is printed to the log if a pre-release is used.
5. MS Visual Studio 2019 is the default compiler.
6. Since I am working with a pre-release version of MSVS 2019 it's possible things will be different on final release.
7. The version I entered for MSVC Platform Toolset is a guess; I don't even know what the toolset is.
I also don't really know what the initial parm block in install_craft.ps1 is about; that didn't stop me from adding an argument in what seemed the right style.