This makes makelibrary.js use environment variables to find paths for plugins, themes and languages instead of just using the paths hardcoded in boot.js
* First pass at dynamic loading/unloading
* Show warning for changes to plugins containing JS modules
* Use $:/config/RegisterPluginType/* for configuring whether a plugin type is automatically registered
Where "registered" means "the constituent shadows are loaded".
* Fix the info plugin
The previous mechanism re-read all plugin info during startup
* Don't prettify JSON in the plugin library
* Indicate in plugin library whether a plugin requires reloading
* Display the highlighted plugin name in the plugin chooser
And if there's no name field fall back to the part of the title after the final slash.
