Doc: Add ability to generate documentation for the module.

-Added targets so that "make docs" will generate the
documentation.

Change-Id: I16a74d7e15e12df16570f110c7e67a110d53afad
Reviewed-by: Michael Goddard <michael.goddard@nokia.com>

doc/config/qtmultimedia_doc.pri

@@ -0,0 +1,35 @@
+
+win32:!win32-g++ {
+    unixstyle = false
+} else:win32-g++:isEmpty(QMAKE_SH) {
+    unixstyle = false
+} else {
+    unixstyle = true
+}
+
+QDOC = $$QT.core.bins/qdoc3
+
+ONLINE_CONF = $$PWD/qtmultimedia.qdocconf
+DITA_CONF = $$PWD/qtmultimedia-dita.qdocconf
+QCH_CONF = #nothing yet
+
+$$unixstyle {
+} else {
+    QDOC = $$replace(QDOC, "qdoc", "qdoc3.exe")
+    ONLINE_CONF = $$replace(ONLINE_CONF, "/", "\\")
+    DITA_DOCS = $$replace(ONLINE_CONF, "/", "\\")
+}
+
+# Build rules
+docs.depends = dita_docs online_docs qch_docs
+
+online_docs.commands = $$QDOC $$ONLINE_CONF
+
+dita_docs.commands = $$QDOC $$DITA_CONF
+
+qch_docs.commands = #no commands yet
+
+QMAKE_EXTRA_TARGETS += docs dita_docs online_docs qch_docs
+QMAKE_CLEAN += \
+               "-r $$PWD/../html" \
+               "-r $$PWD/../ditaxml"