Configuration and logging move out of the context source

context.cpp had grown to hold three unrelated concerns: the context
lifecycle, everything about the .conf file format, and everything about
writing a log message.

conf.cpp now owns the format end to end - parsing a file into the store,
reading values back out, and interpreting a configured string as the
boolean or log level a setting holds. logging.cpp owns the write path:
the level filter, the stream choice, and the name a level carries in
output.

context.cpp keeps what a context is: resolving each setting from the
override, the configured value, or the built-in default, and reporting
what it resolved.

include/internal/context.hpp

@@ -90,14 +90,4 @@ namespace dpm_core {
      * @param msg The failure description
      */
     void set_error(dpm_ctx* ctx, const std::string& msg);
-
-    /**
-     * @brief Loads all configuration files into the context
-     *
-     * Parses every .conf file in the context's configuration directory
-     * into the context's configuration store.
-     *
-     * @param ctx The libdpm-core.so context
-     */
-    void load_config_dir(dpm_ctx* ctx);
 } // namespace dpm_core