Problem with workingsets and temporary area switching

[Alexander Dymo]

Currently when working set is loaded, the workingset controller switches area 
to another one temporarily, modifies the old area (loads views into it) and 
then switches back.

This leads to several problems:
1) mainwindow flicker when you open your first tab (flickering is due to area 
switching)
2) opening the first tab is slow
3) current file isn't focused after startup (not 100% sure that is caused by 
temporary area switching, but can't find other reasons)
4) this is all broken if just one area exists in kdevelop

First problem was severe enough for me to start looking at this.

But svn log says that this switching was done on purpose to
- work well with split views that might already exist in the area
- do not let the user observe documents slowly loading

David, are there any things I need to think about while fixing this?