* updated & cleaned up examples some more
* added features/feature flags to 'common' example boilerplate
* moved xpbd physics to common, behind a flag too
* updated xpbd example
* updated code for bevy_asset_loader changed api
* more cleanups
* fixed issue with "reload registry" not clearing previous data
* added watcher/ poll system to automatically updated the registry & components list when the registry file has been changed
* BREAKING CHANGE ! changed internal representation of components, incompatible with v0.1, breaks UI values.
* added buttons to regenerate UI to account for/fix the above and to offer the ability to regenerate UI values from custom property values
* lots of cleanups
* added tests
* closes#127
* closes#124
* closes#121
* closes#130