Centralize protocol scheme constants

src/main/java/com/scrivenvar/Constants.java

		"definition." + GLOB_PREFIX_FILE;

		- // Different definition source protocols.
		- public static final String DEFINITION_PROTOCOL_UNKNOWN = "unknown";
		- public static final String DEFINITION_PROTOCOL_FILE = "file";
		-
		// Three parameters: line number, column number, and offset
		public static final String STATUS_BAR_LINE = "Main.statusbar.line";

src/main/java/com/scrivenvar/definition/DefinitionFactory.java

		import java.nio.file.Path;

		-import static com.scrivenvar.Constants.DEFINITION_PROTOCOL_FILE;
		import static com.scrivenvar.Constants.GLOB_PREFIX_DEFINITION;
		import static com.scrivenvar.FileType.YAML;

		DefinitionSource result = null;

		- if( DEFINITION_PROTOCOL_FILE.equals( protocol ) ) {
		+ if( ProtocolResolver.isFile( protocol ) ) {
		final FileType filetype = lookup( path, GLOB_PREFIX_DEFINITION );
		result = createFileDefinitionSource( filetype, path );

src/main/java/com/scrivenvar/util/ProtocolResolver.java

		import java.net.URL;

		-import static com.scrivenvar.Constants.DEFINITION_PROTOCOL_UNKNOWN;
		-
		/**
		* Responsible for determining the protocol of a resource.
		*/
		public class ProtocolResolver {
		private static final String SCHEME_HTTP = "http";
		private static final String SCHEME_FILE = "file";
		+ private static final String SCHEME_UNKNOWN = "unknown";

		/**

		result = file.toURI().toURL().getProtocol();
		} catch( final Exception e ) {
		- result = DEFINITION_PROTOCOL_UNKNOWN;
		+ result = SCHEME_UNKNOWN;
		}

Delta	3 lines added, 9 lines removed, 6-line decrease