* Added HTTP API trigger to update running images
* Adds HTTP API authentication token parameter and handling
* Exposes port 8080 in Dockerfile to allow inter-container update triggering via HTTP API
* Fixes codacy issue
* Adds API usage doc
* Fix grammar
* Moves api logic to a package of its own
* Makes WT exit if token has not been set in HTTP API mode
* Adds lock to prevent concurrent updates when in HTTP API mode
Co-authored-by: Simon Aronsson <simme@arcticbit.se>