DERBY-6137: Don't clear the sequence cache during most DDL write operations.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1466481 13f79535-47bb-0310-9956-ffa450edef68
DERBY-6161: Simplify code that handles LOB files

- remove EncryptedLOBFile.close() and let it inherit from super class

- move code that doesn't need privileges out of privileged block in
  LOBStreamControl.init()

- remove unnecessary exception handling in privileged block in
  LOBStreamControl.deleteFile()

- fix typos and misformatted @throws clauses in javadoc comments

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1466503 13f79535-47bb-0310-9956-ffa450edef68
DERBY-6161: Simplify code that handles LOB files

Remove unused method in EngineConnection and BrokeredConnection,
and reduce the visibility of the method with the same name in
EmbedConnection.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1466504 13f79535-47bb-0310-9956-ffa450edef68
DERBY-6162: Simplify privileged actions in NetworkServerControlApiTest

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1466508 13f79535-47bb-0310-9956-ffa450edef68
DERBY-6137: Cleanup cache manager usage by SYSCS_UTIL.SYSCS_PEEK_AT_SEQUENCE.

git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1466522 13f79535-47bb-0310-9956-ffa450edef68