MultiGreeter tests fail with Qt 5.3

Something has changed in Qt with how it interprets the html used in those tests.

Need to check if it's ok (and adapt the tests) or if we need to complain to Qt and fix it there

FAIL! : qmltestrunner::MultiGreeter::test_html_info_prompt() property text
   Actual (): <b>&</b>
   Expected (): &lt;b&gt;&amp;&lt;/b&gt;
   Loc: [/home/tsdgeos_work/phablet/unity8/unity8/tests/qmltests/Greeter/tst_MultiGreeter.qml(297)]

FAIL! : qmltestrunner::MultiGreeter::test_long_info_prompt() property text
   Actual (): Welcome to Unity Greeter

We like to annoy you with super ridiculously long messages.
Like this one

This is the last line of a multiple line message.
   Expected (): Welcome to Unity Greeter<br><br>We like to annoy you with super ridiculously long messages.<br>Like this one<br><br>This is the last line of a multiple line message.
   Loc: [/home/tsdgeos_work/phablet/unity8/unity8/tests/qmltests/Greeter/tst_MultiGreeter.qml(303)]

FAIL! : qmltestrunner::MultiGreeter::test_multi_info_prompt() property text
   Actual (): Welcome to Unity Greeter<br>This is an error<br>You should have seen three messages
   Expected (): Welcome to Unity Greeter<br><font color="#df382c">This is an error</font><br>You should have seen three messages
   Loc: [/home/tsdgeos_work/phablet/unity8/unity8/tests/qmltests/Greeter/tst_MultiGreeter.qml(312)]