LibreSignage v1.1.0-beta-1 release

This is the first beta release for LibreSignage v1.1.0. The full
changelog is included below.

This release includes a rewrite of the server-side API system and major
improvements to all server-side code. Integration tests were also
written for the API.

Another important new feature, made possible by the API rewrite, is the
support for HTTP caching slides. This should improve display performance
quite a bit.

You can begin testing this release by either building from source or by
using the prebuilt Docker images from Docker Hub. The readme has
instructions for building LibreSignage by yourself. Docker images will
appear in the Docker Hub repository as `eerotal/libresignage:v1.1.0-beta-1`
shortly after this tag is pushed into the LibreSignage repository.

Please report any bugs and issues you find in the GitHub bug tracker at
https://github.com/eerotal/LibreSignage/issues

Changelog:

v1.1.0
  - [internal] Separate private and public files in the directory tree
               to naturally prevent access to private files. (PR #56)
  - [feature]  Implement [bgimg] and [bgcolor] markup tags for styling
               slide backgrounds. (issue #75)
  - [feature]  Implement buttons for manual slide navigation in display.
  - [internal] Mostly rewrite the API system
  - [internal] Use PHP autoloading and namespaces instead of direct
               file includes.
  - [internal] Improve various classes and PHP files to make them more
               object oriented.
  - [internal] Implement a testing framework with PHPUnit and write tests
               for all API endpoints.
  - [bugfix]   Fix various bugs in the backend that were discovered while
               writing tests.
  - [build]    Make the build system more modular.
  - [build]    Write separate interactive and CLI versions of the
               apache2-debian target. (apache2-debian-interactive and
               apache2-debian)
  - [build]    Various improvements to the build system.
  - [docs]     Generate documentation with Doxygen.
  - [internal] Implement HTTP cache support for slide asset fetching
               endpoints. (issue #53)
  - [bugfix]   Fix a bug where uploading/removing slide assets was allowed
               even when the slide was not locked. (issue #81)
  - [bugfix]   Fix a bug where a slide could be deleted even when it was
               not locked. (issue #80)

List of contributors and the number of commits by each one:

22  Derek Chafin
295 Eero Talus
This tag has no release notes.