On towards glory

Skogul 0.3.0 contains several changes aimed at project management, some to improve core functionality, and some module improvements. It's not a huge change since 0.2.0, and that's how we like it. As per usual, we aim for high quality releases.

Specific changes:

• Use of CI and automated building of release tar-balls
• Cleanup and refresh of documentation
• There's now a single unified way of handling modules that dramatically reduces code duplication in core.
• Modules can now provide documentation for nested data structures, which is correctly exposed in manual pages.
• A conditional transformer (#71) was added that provides a mechanism to only execute a transformer if certain conditions are present.
• The "extract" feature of the metadata transformer no longer creates empty metadata keys, and will remove the original to avoid duplicating information.
• The logrus receiver replaces the log-receiver, allowing better control of log data. More work in this area is to be expected.
• The HTTP receiver can now apply different authorization rules for different paths.

The latter constitutes a bit of a change in configuration.