During server initialization, establish a connection with the database,
check whether the database schema version is supported, and close the
connection once the server is closing.

This commit also introduces a new section to the configuration file,
`database'.  It allows administrators to define the database server host
and credentials that should be used by the server.

The database schema is not yet being created, the server merely checks
whether the schema table exists, and whether the current database schema
version matches that of the server implementation.  If the database
connection fails, then the server panics.

Additionally, even though some code to close the database connection was
added to the server, it is technically never reached, as the server runs
forever.  However, it's still handy to implement this once graceful
shutdown support is implemented.

@@ -0,0 +34,4 @@
+// This function panics if it's unable to perform its basic task of determining
+// whether the schema table exists (e.g., due to an SQL error).
+func checkDatabaseSchemaExists() bool {
+	query, err := db.Query("SELECT COUNT(ENGINE) FROM information_schema.TABLES WHERE TABLE_SCHEMA='lanbassador' AND TABLE_NAME='schema';")

@@ -55,0 +65,4 @@
+; Defines the password for the database account the server should log in as.
+;password=
+
+; Defines the name of the databse that should be used by the server.  Most

@@ -25,2 +26,4 @@
+	"net/http"
 )
 
+const LANBASSADOR_SERVER_BUFFER_LENGTH = 4096

@@ -0,0 +27,4 @@
+
+const LANBASSADOR_DATABASE_SCHEMA_VERSION = 1
+
+var db *sql.DB

@@ -49,2 +44,3 @@
-	}
+func setCommonResponse(w *http.ResponseWriter) {
+	(*w).Header().Set("Server", "Lanbassador/0.1.0")
 }

@@ -80,0 +93,4 @@
+		w.WriteHeader(http.StatusUnauthorized)
+		setCommonResponse(&w)
+		fmt.Fprintln(w, "Missing or invalid session token.")
+		return false

@@ -0,0 +232,4 @@
+
+	err = query.Scan(&userId, &username)
+	if err != nil {
+		panic(err)

@@ -0,0 +65,4 @@
+
+`CREATE TABLE IF NOT EXISTS users (
+  id INT UNSIGNED NOT NULL PRIMARY KEY AUTO_INCREMENT,
+  username TINYTEXT NOT NULL,

@@ -57,2 +101,2 @@
-		Action: action,
-		Data: data,
+	responseStatusCode := http.StatusOK
+	switch responseCode {

@@ -0,0 +46,4 @@
+		panic(err)
+	}
+
+	return err == nil

@@ -0,0 +36,4 @@
+	LanbassadorDbErrorUnknown = errors.New("An unknown internal error occurred.")
+	LanbassadorDbErrorNoSuchUser = errors.New("No such user.")
+	LanbassadorDbErrorDuplicateEntry = errors.New("A conflicting entry already exists.")
+)

@@ -0,0 +113,4 @@
+}
+
+// Closes the opened database engine.  Must only be called after initDatabase.
+func closeDatabase() {