Fix#5373.
- Remove references to removed file "../../build/deps.js"
- Update leaflet-include.js to point to "../dist/leaflet-src.js"
- Update watch to use the same destination file as rollup (dist/leaflet-src.js)
- Define getRandomLatLng where used
- default offset is now [0, 0]
- both offset.x and offset.y are always honoured
- positive x always move the tooltip on the right
- positive y always move the tooltip on the bottom