Fix: Pascal Scripting: Using event function CurInstallProgressChanged would result in runtime errors.

Fix for download error

- Changes:
- Directories junctions are represented in the subdirectory tree by their own icon
- All types of links are recognized, including cloud links, for example
- Standard directories are retrieved using the Win API function SHGetKnownFolderPath
(available since Vista).
- PbWatchdog can be triggered to backup the changed files immediately
by the additional program PbForceWatchdog
- Bug fixes:
- Sometimes the program froze while running in the background and
the monitor is turned off when calling the system routine “LpkGetTextExtentExPoint”
in the module “gdi32full.dll” (possibly depending on the installed graphics driver)