Fixed ordering problem when configuring with `-make <part>'

Prior to this change, running configure with the `-make' option would
affect the order in which parts of Qt are built.  This is unintuitive
and would easily cause build failures.  For example, configuring with
`./configure -make demos' would attempt to build demos before building
libs, which, of course, would fail.

Refactor the code so that the result is the same regardless of the order
of `-make' options.

Change-Id: Idfa61834a0f01d0628a9a1ae27ece94ae3647e6d
Reviewed-on: http://codereview.qt.nokia.com/128
Reviewed-by: Lincoln Ramsay <lincoln.ramsay@nokia.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@nokia.com>

qtbase.pro

@@ -13,20 +13,30 @@ module_qtbase_tests.depends = module_qtbase_src
 module_qtbase_tests.CONFIG = no_default_install
 
 #process the projects
-for(PROJECT, $$list($$lower($$unique(QT_BUILD_PARTS)))) {
-    isEqual(PROJECT, examples) {
-       SUBDIRS += examples
-    } else:isEqual(PROJECT, demos) {
-       SUBDIRS += demos
-    } else:isEqual(PROJECT, tests) {
-       SUBDIRS += module_qtbase_tests
-    } else:isEqual(PROJECT, libs) {
-       include(src/src.pro)
-    } else:isEqual(PROJECT, qmake) {
-#      SUBDIRS += qmake
-    } else {
-       message(Unknown PROJECT: $$PROJECT)
-    }
+PROJECTS=$$eval($$list($$lower($$unique(QT_BUILD_PARTS))))
+# note that the order matters for these blocks!
+contains(PROJECTS, qmake) {
+    PROJECTS -= qmake
+    # nothing to be done
+}
+contains(PROJECTS, libs) {
+    PROJECTS -= libs
+    include(src/src.pro)
+}
+contains(PROJECTS, examples) {
+    PROJECTS -= examples
+    SUBDIRS += examples
+}
+contains(PROJECTS, demos) {
+    PROJECTS -= demos
+    SUBDIRS += demos
+}
+contains(PROJECTS, tests) {
+    PROJECTS -= tests
+    SUBDIRS += module_qtbase_tests
+}
+!isEmpty(PROJECTS) {
+    message(Unknown PROJECTS: $$PROJECTS)
 }
 
 !symbian: confclean.depends += clean