DBServer: YAML Engine skeleton.
YAMLEngine: Handle id management.
DBServer: Add do_id handling to YAMLDatabase.
DBServer: Add YamlDatabase to build config.
DBServer: Separate test_db_filesystem into its own file, and add test_db_yaml.
YAMLDatabase: Output fields on create_object (as human readable data).
YAMLDatabase: Implement get_object()
YAMLDatabase: Combine multi-line stream output operations.
YAMLDatabase: Use const string reference instead of just string
YAMLDatabase: Add helper to pack field into std::string from yaml node.
DBServer: Add spam/debug messages to select_all
Merge master && binary-data refactor into kestred-yaml

Conflicts:
	src/database/DatabaseServer.cpp
YAMLDatabase: Update yamldb to use vector<uchar> for binary values instead of string.
DBServer: Switch default database type to yaml.
Merge branch 'kestred-yaml' into dbserver

Conflicts:
	src/database/DatabaseServer.cpp
Compile-errors:
	src/database/YAMLEngine.cpp
DBServer: Add missing newline in log output.
Tests: Database Server test for DBSERVER_UPDATE_STORED_OBJECT
Tests: Add Database Server test for UPDATE_STORED_OBJECT_IF_EQUALS.
Database Server: Use return codes in protocol instead of boolean success.
Tests: Add Database Server test for UPDATE_IF_EQUALS with invalid fields