adding python to *.py package calls

  - under windows we had the problem that *.py needs to be registered and
    even if we had it: a call with modified PATH variable resulted in
    strange two PATH variables in the environment (not sure that this was
    a problem of nmake or something else)
  - added -u to get the output unbuffered

Change-Id: I9326a31fc39a95b61d92bb00549f536db04af985
Reviewed-by: Matti Paaso <matti.paaso@digia.com>
Reviewed-by: Iikka Eklund <iikka.eklund@digia.com>

qtcreator.pro

@@ -73,7 +73,7 @@ macx {
 } else {
     BINDIST_SOURCE = "$(INSTALL_ROOT)$$QTC_PREFIX"
     BINDIST_INSTALLER_SOURCE = "$$BINDIST_SOURCE/*"
-    deployqt.commands = $$PWD/scripts/deployqt.py -i \"$(INSTALL_ROOT)$$QTC_PREFIX\"
+    deployqt.commands = python -u $$PWD/scripts/deployqt.py -i \"$(INSTALL_ROOT)$$QTC_PREFIX\"
     deployqt.depends = install
     win32 {
         deployartifacts.depends = install
@@ -94,7 +94,7 @@ bindist.commands = 7z a -mx9 $$OUT_PWD/qt-creator-$${PATTERN}.7z \"$$BINDIST_SOU
 bindist_installer.depends = deployqt
 bindist_installer.commands = 7z a -mx9 $${INSTALLER_ARCHIVE} \"$$BINDIST_INSTALLER_SOURCE\"
 installer.depends = bindist_installer
-installer.commands = $$PWD/scripts/packageIfw.py -i \"$(IFW_PATH)\" -v $${QTCREATOR_VERSION} -a \"$${INSTALLER_ARCHIVE}\" "$$INSTALLER_NAME"
+installer.commands = python -u $$PWD/scripts/packageIfw.py -i \"$(IFW_PATH)\" -v $${QTCREATOR_VERSION} -a \"$${INSTALLER_ARCHIVE}\" "$$INSTALLER_NAME"
 
 macx {
     # this should be very temporary: