Support jtds SQL integrated security

 <jdbc-datasource>
    <url>jdbc:jtds:sqlserver://dbserver:1439/JIRADB</url>
    <driver-class>net.sourceforge.jtds.jdbc.Driver</driver-class>
    <username>windowsUser</username>
  </jdbc-datasource>

    In order for Single Sign On to work, jTDS must be able to load the native
    SPPI library (ntlmauth.dll). Place this DLL anywhere in the system path
    (defined by the PATH system variable) and you're all set.

2013-04-11 14:48:30,861 localhost-startStop-1 ERROR      [atlassian.jira.startup.LauncherContextListener] Unable to start JIRA.
com.atlassian.jira.util.dbc.Assertions$NullArgumentException: username should not be null!
	at com.atlassian.jira.util.dbc.Assertions.notNull(Assertions.java:28)
	at com.atlassian.jira.util.dbc.Assertions.notBlank(Assertions.java:112)
	at com.atlassian.jira.config.database.JdbcDatasource.<init>(JdbcDatasource.java:177)
	at com.atlassian.jira.config.database.JdbcDatasource.<init>(JdbcDatasource.java:30)
	at com.atlassian.jira.config.database.JdbcDatasource$Builder.build(JdbcDatasource.java:605)
	at com.atlassian.jira.config.database.JdbcDatasource.parse(JdbcDatasource.java:408)
	at com.atlassian.jira.config.database.DatabaseConfigHandler.parseDatasource(DatabaseConfigHandler.java:73)
	at com.atlassian.jira.config.database.DatabaseConfigHandler.parse(DatabaseConfigHandler.java:33)
	at com.atlassian.jira.config.database.AbstractJiraHomeDatabaseConfigurationLoader.loadDatabaseConfiguration(AbstractJiraHomeDatabaseConfigurationLoader.java:57)
	at com.atlassian.jira.startup.SystemTenantProvider.getSystemDatabaseConfig(SystemTenantProvider.java:69)
	at com.atlassian.jira.startup.SystemTenantProvider.getSystemTenant(SystemTenantProvider.java:46)
	at com.atlassian.multitenant.MultiTenantContext.getSystemTenant(MultiTenantContext.java:473)
	at com.atlassian.multitenant.MultiTenantContext.defaultInit(MultiTenantContext.java:112)
	at com.atlassian.jira.startup.LauncherContextListener.initMultiTenantSystem(LauncherContextListener.java:145)
	at com.atlassian.jira.startup.LauncherContextListener.contextInitialized(LauncherContextListener.java:69)
	at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4791)
	at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5285)
	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
	at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
	at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
	at java.util.concurrent.FutureTask.run(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.lang.Thread.run(Unknown Source)