2. add UT.

* change position of EncryptCondition's positionValueMap & positionIndexMap

* move generate EncryptConditions from optimize to rewrite module

* remove EncryptConditionOptimizedStatement.encryptConditions

* move encrypt condition to rewrite module

* remove EncryptWhereOptimizeEngine

* remove useless parameter for EncryptOptimizeEngineFactory.newInstance()

* remove EncryptTransparentOptimizedStatement

* remove EncryptOptimizedStatement

* remove ShardingTransparentOptimizedStatement

* remove ShardingOptimizedStatement

* remove rule parameter for OptimizeEngine.optimize()

* remove EncryptOptimizeEngineFactory

* rename ShardingOptimizeEngineFactory to OptimizedStatementFactory

* rename ShardingSelectOptimizedStatement to SelectOptimizedStatement

* Fix SCTL statement execute error with comment

* Add  SCTLUtils class to trim sql

* 
1. modify MySQLAuthenticationHandler's login method to return Optional<ProxyUser>.
2. check response41 database with ProxyUser's database.
3. add UT.

* resolve conflicts.

* try CI check again.

* 
1. move schema judgement to MySQLAuthenticationHandler.
2. modify UT.

* 
1. modify the input parameter of MySQLAuthenticationHandler.login().
2. modify UT.

* try CI check again.

* 
1. add ER_DBACCESS_DENIED_ERROR in MySQLServerErrorCode.
2. modify the result of MySQLAuthenticationHandler.login() to Optional<MySQLServerErrorCode>.
3. modify UT classes.

* delete ShardingDropIndexOptimizedStatement

* avoid using ShardingConditionOptimizedStatement

* remove ShardingConditionOptimizedStatement

* decouple GeneratedKey and columnNames

* refactor InsertClauseShardingConditionEngine

* refactor InsertClauseShardingConditionEngine's constructor

* move GeneratedKey from optimize module to route module

* rename package name org.apache.shardingsphere.core.optimize.sharding.segment.select to org.apache.shardingsphere.core.optimize.sharding.segment

* merge ShardingInsertOptimizedStatement and EncryptInsertOptimizedStatement to InsertOptimizedStatement

* rename OptimizedStatement.getSQLStatement() to getSqlStatement

* remove ShardingOptimizeEngine & EncryptOptimizeEngine

* move constant of derived values from optimize module to rewrite module

* Update StandardRoutingEngineTest.java

* Update ComplexRoutingEngineTest.java

* Merge branch 'dev' of https://github.com/apache/incubator-shardingsphere into issue3061

# Conflicts:
#	sharding-core/sharding-core-route/src/test/java/org/apache/shardingsphere/core/route/type/complex/ComplexRoutingEngineTest.java
#	sharding-core/sharding-core-route/src/test/java/org/apache/shardingsphere/core/route/type/standard/StandardRoutingEngineTest.java

* Fix spring-boot-plugin version missing bug.

* Support jdk1.7 to change frontend-maven-plugin version

* For #3032, add missing dcl test cases for select with functions grammars.

* For #3032, add missing dcl test cases for select with functions grammars 2nd.

* For #3047, Refactor TableBroadcastRoutingEngineTest

* For #3047, Add some unit test for exception

* For checkstyle

* For #3047, Add unit test log SQL shard with parameters

* For #3047, Add unit test for SPIRoutingHook

* For #3047, Add unit test for RoutingUnit

* For #3047, Add unit test for RoutingResult

* For #3047, Add unit test for BatchRouteUnit

* For #3047, Add unit test for MasterInstanceBroadcastRoutingEngine

* For #3047, Add unit test for MasterSlaveRouter

* For #3047, Add unit test for ShardingMasterSlaveRouter

* For #3047, Add equals and toString unit test for BatchRouteUnit, RouteUnit and SQLUnit

* For #3047, Refactor StandardRoutingEngineTest

* For #3047, Refactor ComplexRoutingEngineTest

* For #3047, Refactor AbstractSQLRouteTest and for checkstyle

* For #3047, Add assertToString for RoutingUnit and TableUnit

* For #3047, Add unit test for RoutingEngineFactory

* For #3047, Add unit test for insert

* For #3047, Conflict resolution

* For #3047, Add unit test for InlineShardingStrategy

* remove RoutingResultValidator

* rename org.apache.shardingsphere.core.route.router.sharding.validator.statement to org.apache.shardingsphere.core.route.router.sharding.validator

* update javadoc

* add judge to whether routed data sources belong to configured data sources

* remove ShardingRouter

* rename ParsingSQLRouter to ShardingRouter

* move ShardingConditions from optimize module to route module

* move ShardingConditions from optimize module to route module

* add ShardingRouter.getShardingConditions()

* revise error message for ShardingDropIndexOptimizeEngine

* change signature of RoutingEngineFactory.newInstance()

* move drop index's logic from optimize to route module

* remove ShardingDropIndexOptimizeEngine

* add ShardingValidator

* refactor ShardingUpdateValidatorTest

* add ShardingInsertValidatorTest

* remove UpdateStatement & DeleteStatement

* For #3032, add missing dcl test cases for alter relative grammars.

* For #3032, add missing dcl test cases for alter relative grammars 2nd.