[Development] Very slow incremental builds with 5.8

[Edward Welbourne]

Sean Harmer:
>>> what is the reason that when doing incremental builds with the 5.8
>>> branch that qmake gets run in each and every subdir please? It
>>> *really* slows down doing incremental builds. Is there any way to
>>> avoid this or can we go back to the 5.7 behaviour please?

I can confirm this is just the make files - Creator is not the culprit -
as I'm building purely using make and seeing the same.

	Eddy.