Split SQL Server Platform into SqlServer16 and SqlServer17

[wenbin151]

When Ebean starts with SqlServer detected ... and no explicit platform choice is made Ebean will fail to start asking you to chose the preferred platform (2017 or 2018).

https://github.com/ebean-orm/ebean/issues/1340
For SqlServer please choose the more specific sqlserver16 or sqlserver17 platform via ServerConfig.setDatabasePlatformName. Refer to issue #1340 for details
` javax.persistence.PersistenceException: java.lang.IllegalArgumentException: For SqlServer please choose the more specific sqlserver16 or sqlserver17 platform via ServerConfig.setDatabasePlatformName. Refer to issue #1340 for details

at io.ebeaninternal.server.core.DatabasePlatformFactory.create(DatabasePlatformFactory.java:62)
at io.ebeaninternal.server.core.DefaultContainer.setDatabasePlatform(DefaultContainer.java:266)
at io.ebeaninternal.server.core.DefaultContainer.createServer(DefaultContainer.java:126)
at io.ebeaninternal.server.core.DefaultContainer.createServer(DefaultContainer.java:45)
at io.ebean.EbeanServerFactory.createInternal(EbeanServerFactory.java:109)
at io.ebean.EbeanServerFactory.create(EbeanServerFactory.java:70)
at io.ebean.config.ServerConfigSqlServerTest.need_explicitPlatform(ServerConfigSqlServerTest.java:35)`

[wenbin151]

修复方式：

act.db.sql.DataSourceConfig

增加 public String databasePlatformName; 属性

在DataSourceConfig构造函数中增加此属性的判断加载，

if (url.contains("sqlserver")) {
     	if(get(conf, "databasePlatformName")!=null) {
       		databasePlatformName=get(conf, "databasePlatformName");
       	}	
}

act.db.ebean.ServerConfig

然后在ebean中设置ServerConfig时，判断是 sqlserver 驱动就把这个ServerConfig.setDatabasePlatformName 了。

不然启动会报如下错误：

2018-05-03_01:34:58.555 [jobs-thread-3] ERROR act.app.App - Block issue encountered
org.osgl.exception.ConfigurationException: Error init SQL db service
	at org.osgl.util.E.invalidConfiguration(E.java:291)
	at act.db.sql.SqlDbService$1.run(SqlDbService.java:116)
	at act.db.sql.SqlDbService$1.on(SqlDbService.java:77)
	at act.event.EventBus.callOn(EventBus.java:1313)
	at act.event.EventBus.access$1400(EventBus.java:53)
	at act.event.EventBus$4.run(EventBus.java:1342)
	at act.job.JobManager$ContextualJob$1.apply(JobManager.java:461)
	at act.job.Job.doJob(Job.java:345)
	at act.job.Job.run(Job.java:282)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
Caused by: javax.persistence.PersistenceException: java.lang.IllegalArgumentException: For SqlServer please explicitly choose either sqlserver16 or sqlserver17 as the platform via ServerConfig.setDatabasePlatformName. Refer to issue #1340 for more details
	at io.ebeaninternal.server.core.DatabasePlatformFactory.create(DatabasePlatformFactory.java:66)
	at io.ebeaninternal.server.core.DefaultContainer.setDatabasePlatform(DefaultContainer.java:266)
	at io.ebeaninternal.server.core.DefaultContainer.createServer(DefaultContainer.java:126)
	at io.ebeaninternal.server.core.DefaultContainer.createServer(DefaultContainer.java:45)
	at io.ebean.EbeanServerFactory.createInternal(EbeanServerFactory.java:109)
	at io.ebean.EbeanServerFactory.create(EbeanServerFactory.java:70)
	at act.db.ebean.EbeanService.dataSourceProvided(EbeanService.java:91)
	at act.db.sql.SqlDbService.initDataSource(SqlDbService.java:210)
	at act.db.sql.SqlDbService.access$000(SqlDbService.java:51)
	at act.db.sql.SqlDbService$1.run(SqlDbService.java:90)
	... 14 common frames omitted
Caused by: java.lang.IllegalArgumentException: For SqlServer please explicitly choose either sqlserver16 or sqlserver17 as the platform via ServerConfig.setDatabasePlatformName. Refer to issue #1340 for more details
	at io.ebeaninternal.server.core.DatabasePlatformFactory.byDatabaseMeta(DatabasePlatformFactory.java:150)
	at io.ebeaninternal.server.core.DatabasePlatformFactory.byDataSource(DatabasePlatformFactory.java:123)
	at io.ebeaninternal.server.core.DatabasePlatformFactory.create(DatabasePlatformFactory.java:63)
	... 23 common frames omitted

[greenlaw110]

@wenbin151 你发个 PR 我来 merge