This is split off from 5050516.

There are 2 problems left:
  1) JFileChooser scans directories before it is actually shown.
     This might impact startup for some applications and may be unneeded work
     if directory will be changed before displaying filechooser window.

  2) Monitoring files opened using filemon utility it seems that some extra work is performed.
     In particular:
        - files from different directories are accessed
        - there are multiple requests for desktop.ini file in several different directories
        - requests for some dlls are triggered (possible that these are apps associated with
           files from directory). Here is example:

1286 4:07:59 PM java.exe:1300 QUERY INFORMATION C:\Program Files\Common Files\Ahead\Lib\NeroDigitalExt.dll SUCCESS Attributes: A
1290 4:07:59 PM java.exe:1300 QUERY INFORMATION C:\Program Files\Common Files\Ahead\Lib\NeroDigitalExt.dll SUCCESS Length: 1802240
1295 4:07:59 PM java.exe:1300 QUERY INFORMATION C:\Program Files\Common Files\Ahead\Lib\NeroDigitalExt.dll SUCCESS Attributes: A
1296 4:07:59 PM java.exe:1300 QUERY INFORMATION C:\Program Files\Common Files\Ahead\Lib\NeroDigitalExt.dll SUCCESS Length: 1802240
1301 4:07:59 PM java.exe:1300 QUERY INFORMATION C:\Program Files\Adobe\Acrobat 7.0\ActiveX\PDFShell.dll SUCCESS Attributes: A
1305 4:07:59 PM java.exe:1300 QUERY INFORMATION C:\Program Files\Adobe\Acrobat 7.0\ActiveX\PDFShell.dll SUCCESS Length: 110592
1310 4:07:59 PM java.exe:1300 QUERY INFORMATION C:\Program Files\Adobe\Acrobat 7.0\ActiveX\PDFShell.dll SUCCESS Attributes: A
1311 4:07:59 PM java.exe:1300 QUERY INFORMATION C:\Program Files\Adobe\Acrobat 7.0\ActiveX\PDFShell.dll SUCCESS Length: 110592

Disk access is very expensive. We should try to avoid (triggering) extra disk operations.