Minor bugfix and tweaks

Fixed

• Improved detection for projects. Previously if projects had been in use and were then disabled, uibuilder would still think them active.

Changed

• Add a new example to the library: cacheByTopic - A simple caching example that uses a function node to cache the last msg for each topic & replay them when a client connects.
• Improved initial debug msg in the front-end (if debug=true), shows versions and whether the minimised version of uibuilderfe is in use.
• Code safety improvements and tidy up.
• Slight tweak to the default template (VueJS). The button now has an ID and the increment function prints out the event object to console.