Add page break character.
Servant not only for integration tests.
Not using rx.
No need for key binding or message in servant.

The server runs as a background job.
Change code styling.
Update copyright years.
Delete sandbox files.
Update and improve unit tests.
Fix broken links support.
Caskify takes bundle as argument.
Simplify and remove some Ecukes tests.

Test more with unit tests.
Update Makefile.
Update Travis configuration.
Merge branch 'test-improvements' into v0.6-wip