qmake contains() function second argument is a regex.

Current documentation for the contains() function:

http://qt-project.org/doc/qt-5.0/qtdoc/qmake-test-function-reference.html#contains-variablename-value

does not say that the second argument (called "value") is actually treated as a regular expression.

From the latest code it also seems that contains may accept 3 arguments, but I have hard time understanding the intent. It looks like the third argument could be used to further restrict the match to a list of possible values, but the regex is still required.