feature(plugin): Introduce "Clean Branches" plugin, currently as a workaround for a bug in the vcs.go code. 🐞

feature(project): When running project scripts, support the logging of all output within the artifacts, and echo stderr to the console when a script fails 📝

feature(metrics): Wrap calls to plugin functions with the Sentry/Raven `CapturePanic` wrapper to report plugin errors 📝

chore(documentation): Improve documentation, introduce an index-generator template (currently unused) based on Material Design. 📝

feature(plugin): Initial commit of the index-generator plugin; It doesn't generate indexes just yet but does put cool badges in the artifacts directory for use in your markdown files!

Be clever with the destination parent: Split the destination into a slice, pop the last item off the end, and reassemble the path string. 💪

Better handling of artifact paths to support branch names with slashes (will be nested as subdirectories) 📦

Support for building branches with more than 3 segments in the ref (such as git-flow style bug/feature branches) ✨

Debug level logging when  pulling changes (local merging / fast forwarding) for better troubleshooting 🔍

Projects will now continue to build when a one or more branches fail, giving each branch it's own chance to build. 🌱

Plugin: All-Branches: Don't build all branches unless the project has been configured as such (one branch defined as wildcard in the config)

Plugins: Introduce the `all-branches` plugin, which brings crude wildcard support for building all remote branches. 🤖

Also, move each plugin into it's own dir to prevent package collisions and update makefile accordingly. 📦

* feature/plugin-support:
  Plugin interface uses memory pointers, so that plugins can directly manipulate variables being used in the program. 🔌✨
  Getting closer to a usable plugin interface, there are now variables passed to the plugin "hooks" 🔌
  Docker: Build default plugins along with the main binary, before packing 🐳
  Makefile: Build plugins with `make build-plugins`, don't auto-rebuild everything
  Better public/private-ness of types and variables, better plugin example, first actually-working basic plugin interface. ✨
  Makefile support for creating non-stripped builds with full debug support.
  Make all types and structs public 💪
  Robustness and logging in the extension/plugin loader 🤜🤛 🔌
  Update Makefile to build from `src` directory 🛫
  Modularise code and move into src subdirectory 🦕
  Ignore `.idea` directory (when using IntelliJ / GoLand or similar) ☕
  Update plugin example and document plugin configuration 📝
  Begin work on modularisation, documentation, and plugin support

Plugin interface uses memory pointers, so that plugins can directly manipulate variables being used in the program. 🔌✨

Better public/private-ness of types and variables, better plugin example, first actually-working basic plugin interface. ✨

(NB: Should be compatible with dlv when run under go 1.9, however due to https://github.com/golang/go/issues/23733 go 1.10 and 1.11 will cause dlv to produce an error)