Revert "[BACKLOG-26] Temporary disable create datasource for home screen. There is old bug with scrolling. See http://jira.pentaho.com/browse/BACKLOG-26?focusedCommentId=193810&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-193810 for details"

This reverts commit 6036dbd08e33beb6c953e74589ec43373261819d.
Merge pull request #488 from AlexanderBuloichik/BACKLOG-26d

Revert "[BACKLOG-26] Temporary disable create datasource for home screen...
[CLEANUP] Data access check style clean up
Merge pull request #490 from scottyaslan/devBranch

[CLEANUP] Data access check style clean up
BACKLOG-614 - CLONE - If a user attempts to create a new connection with the same name the overwrite dialog displays, when user selects Yes an error occurs

Fix set id of connection for overwriting correctly (change service method "isConnectionExist" to return id of connection).
If edit connection and use existing name and confirm overwrite than one of connections is deleted and one is updated.