Add convenience function for unblocking a `ws_connbuf`
Use unblocking function in ws_connbuf itself
Use new convenience function in connector
Add context to action manager
Pass context to transactions being run
Add CMake module for finding the GBM library
Use GBM in build env
Add GBM device member to framebuffer device
Add EGLDisplay member to framebuffer device
Merge pull request #417 from neithernut/add-action_manager-global_context_usage

Add global context usage to action manage
Add initial, basic egl buffer type
Add pop command
Add implementation of (de)init
Add push command
Merge pull request #376 from neithernut/add-compositor-egl_cap

Add egl capabilities to compositor
Merge pull request #414 from matthiasbeyer/add-commands_push_pop

Add pop/push command
Add structure for user documentation
Merge pull request #403 from matthiasbeyer/add-user_doc_structure

Add structure for user documentation
Merge pull request #405 from neithernut/add-connbuf-unblocking_convenience_macro

Add connbuf unblocking convenience macro