Merge #6880 test from 6.8; fix itself is not needed in Vaadin 7

svn changeset:25925/svn branch:6.8
svn changeset:25928/svn branch:6.8

Change-Id: I89e6f30d7d04f9511e26121f860f846bef7ec17d
SQLContainer.indexOfId() also searches backwards (#11849, #10376)

Change-Id: Iea3f832cd50314f747b82b774c3be57797f9ac1d
Test for #11267 adapted from 6.8. 

The problem is not present in 7, but you need to use a slightly different css to acieve the same result.

Change-Id: Iee6907a15fd9b0674dcb490f9110fc762c56deb6
Ticket: 11267
Merge changes from origin/7.1

1a6200e Merge #6880 test from 6.8; fix itself is not needed in Vaadin 7
67696f3 SQLContainer.indexOfId() also searches backwards (#11849, #10376)
0a437a5 Revert "Replaced css inject hack in TestUtils with Page.Styles.add() #11798"
611e5f9 Test for #11267 adapted from 6.8.

Change-Id: Idb91964c495a7d46ebf468896ff968a35c417397