Refactor lifts to be a plugin
Fix require paths after moving files
Change the place where we keep timestamp
Fix rendering for plugins
extract DB related operations to a separate module
enable plugin registration

separate plugins module is responsible for maintaining plugins
repository
'lifts' plugin is registered by default
app.plugins.register(name, module) - can be called to add additional
plugins
use async module
separate loaders to allow for async data init

After moving resort loaders to a separate files, data module is now
responsible for loading resorts.

The initialization is now asynchronous: we don't start the server until
it's completed.
fix request counter implementation

only increment the request counter if resort details are open (iow: only
if something asks for details of this specific resort)

otherwise opening main liftie page will always cause counter to be
incremented
Merge remote-tracking branch 'origin/plugins'