Fix to random build directory removing problem

At least in Windows 8.1 we have random problem that build directory
can't be removed for some reason. When repeating this manually you may
need to run remove command twice to make build directory disappear.

Command will wait 5 second if it can't remove build directory at the
first try. After 5 second it will try to remove it again.

Change-Id: I5b5064f523693ddbed392993acd3b1a587e0ca87
Reviewed-by: Tony Sarajärvi <tony.sarajarvi@digia.com>
QtTools, QtWebChannel, QtWebEngine: set some configs enforcing

These are passing.  Make sure they stay that way.

Change-Id: Ia2f56baf2187f53f4f4c557e7d357f8d9efe87b6
Reviewed-by: Heikki Halmet <heikki.halmet@digia.com>
Change qt5 checkout to work with submodule references

Change-Id: I42bc0512adcbe960cc5327137efcdcde676303b1
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@digia.com>