[KDev4] going back to blocking project open.

[dukju ahn]

Although it was me that proposed to make project openning ASync,
I didn't forcast many possible complexities when we use thread.
Now I carefully suggest that we go back to the original blocking mode

1.
The QObject cannot be created in the context of project parsing thread.
Reason is that according to Qt-Doc,
"You must ensure that all objects created in a thread are deleted before
you delete the QThread"

To workaround this, we can choose to hold the thread during the entire
period of time when the project is loaded. But I'm not sure that's a
right approach

2.
I doubt the benefit of live GUI when the project is not loaded.
Especially, when the user is loading the first project, there is nothing
for the user to compose a file. In many case, the user will just wait the
completion of parsing, even though he has a live GUI.

3.
I found the reason of slow project loading -- the KIO::pixmapForUrl() which
is called to provide argument to setIcon(), which
is called whenever the item are created. If we don't setIcon() at project
parsing and rather setIcon() at the time of directory expansion, the
time is reduced.

The measure result is for loading full kdelibs source using custom make manager,
when icons are set
kdevelop: Project Loading 124695 Milisecs are elapsed
but when icons are not set.
kdevelop: Project Loading 6451 Milisecs are elapsed

4.
The KConfig cannot be used in thread.

I'm very sorry, I should have anticipated these problems..