Automatically prefix all log messages with the plugin name (if available).
Include strings.h instead of defining _BSD_SOURCE to get strcasecmp. _BSD_SOURCE is deprecated in favor of _DEFAULT_SOURCE but also it's not needed for strcasecmp() when including strings.h in addition to string.h.
Replaced sdb_store_<type> with sdb_plugin_store_<type>. That is, all store updates will now directly go through the plugin API and be distributed to all store-writer plugins from there.
Use stdbool.h's bool type instead of _Bool. That'll work with C++ as well.
Moved backends from src/backend/ to src/plugins/backend/.