Port QDesktopServices

[Dmitry A. Kuminov]

Provide the OS/2 version of the QDesktopServices class.

[Dmitry A. Kuminov]

Created the dummy implementation in r132. The real functionality (things like opening URLs) is irrelevant for the beta.

[Dmitry A. Kuminov]

Implemented in r486. Below are some remarks about the implementation.

In the absence of the native guidelines, locations in the DesktopServices::storageLocation() call that don't have de facto standard values on the OS/2 platform, are interpreted according to the XDG guidelines (used on Linux). The following table summarizes it (parenthesis contain the default if the value isn't explicitly specified):

location	value
HomeLocation	QDir::homePath()
TempLocation	QDir::tempPath()
CacheLocation	%XDG_CACHE_HOME% (%HOME%/.cache) [*1]
DataLocation	%XDG_DATA_HOME% (%HOME%/.local/share) [*1]
DesktopLocation	XDG_DESKTOP_DIR [*2] (WinQueryActiveDesktopPathname()))
DocumentsLocation	XDG_DOCUMENTS_DIR [*2] (%HOME%/Documents)
PicturesLocation	XDG_PICTURES_DIR [*2] (%HOME%/Pictures)
MusicLocation	XDG_MUSIC_DIR [*2] (%HOME%/Music)
MoviesLocation	XDG_VIDEOS_DIR [*2] (%HOME%/Videos)
ApplicationsLocation	%PROGRAMS% (<boot_drv>:/PROGRAMS)
FontsLocation	%FONTS% (<boot_drv>:/PSFONTS)

[*1] See ​http://standards.freedesktop.org/basedir-spec/basedir-spec-0.6.html for the full explanation.
[*2] See ​http://www.freedesktop.org/wiki/Software/xdg-user-dirs for the full explanation.

QDesktopServices::displayName() on OS/2 reurns nothing, same as on Windows and Linux.

QDesktopServices::openUrl() uses the HINI_USER_PROFILE\WPURLDEFAULTSETTINGS registry key to determine the default web browser, e-mail client and other supported applications. On a modern eCS system, that means that clicking URLs in Qt applications will open Firefox/Thunderbird out of the box.

If the URL to open is a local file or directory, WPS associations will be used to open it.