Improve command line parsing

Improve command line argument parser.  This will make it easier to add
code to read command line options (which previously weren't available).

src/main.cxx

@@ -47,25 +47,25 @@ void printIntro() {
 int main(int argc, char *argv[]) {
 	printIntro();
 
-	std::string path;
+	std::string path = "";
 
 	// Parse cmdline options
-	switch (argc) {
-		case 1:
-			path = ".";
-			std::cout << "Assuming working directory is \".\""
-				<< std::endl;
-			break;
-		case 2:
-			path = argv[1];
-			std::cout << "Using specified directory: "
-				<< path << std::endl;
-			break;
-		default:
+	for (int argi = 1; argi < argc; argi++) {
+		if (argv[argi][0] == '-') {
+			// This is a cmdline option (starts with a dash).
+
+		} else if (path == "") {
+			path = argv[argi];
+		} else {
+			std::cerr << "error: website directory was already " <<
+				"provided (`" << path << "'), refusing to continue with `" <<
+				argv[argi] << "'.\n";
 			printUsage(argv[0]);
 			exit(RETURN_FAILED_INVALID_SYNTAX);
-			break;
 		}
+	}
+
+	std::cout << "Using specified directory: " << path << "\n";
 
 	SwgContext ctx;
 	parse_config(&ctx, path);