DOC: Removed Doxygen \example tags for Tests.

Several \example tags were using Test files are targets. This was producing
warnings in Doxygen, since the path to the actual files was not propely
specified. Given that the Test files themselves are not good examples for
users, here we opt for removing the references altogether.

Change-Id: I8871cfd5eae5ba7ae08f92c7d80ca22ea07e976e
Merge topic 'RemoveBogusDoxygenExamples'

911b292 DOC: Removed Doxygen \example tags for Tests.