Conflicts:
	src/app/core/cache/builders/remote-data-build.service.ts

Fetching and parsing browse entries

Set ip and port by an env variable.

Mock AdminGuard

For docker containers it would be useful if any configuration variables
defining how to connect to the angular ui and how it connects to the
DSpace 7 REST endpoint could be overriden by environment variables. We
should not extend configuration by environment variables too much.

This PR closes #160

# Conflicts:
#	src/app/app.component.ts
#	src/app/core/core.module.ts

Search service implementation