Add kommodity library

Kommodity is a Qt wrapper for GIO that allows us to use GIO and GVFS.

svn co svn://anonsvn.kde.org/home/kde/trunk/playground/libs/kommodity
Port Kommodity to Qt 5

Kommodity now builds with Qt 5.
Link to kommodity

Turn kommodity into a static library and link Swordfish to it.
Fix build

Fix build by using the right include directories.
Don't install Kommodity headers

Kommodity is a static library we don't need to install its headers.
Kommodity in include directories

Add Kommodity include directories.
Find all Vibe dependencies

We need all Vibe libraries.
Places model and bookmarks

Implement PlacesModel and bookmarks.
Kommodity now depends on Qt5Gui too

We'll need to write methods to convert GIO icons to QIcon, hence
we depend on Qt5Gui now.
Convert GIO icons to QIcon

Added a new method to Kommodity::Icon in order to convert icons to
QIcon.

This feature is needed by some classes such as PlacesModel.
Recognize icon type and convert to QIcon accordingly

If we are dealing with a GFileIcon, g_icon_to_string() might return
a path. If that's the case we need to tell QIcon, otherwise we assume
it's an icon name but if the current theme doesn't have it we load
the "unknown" icon.

See also https://developer.gnome.org/gio/2.32/GIcon.html#g-icon-to-string
Added new default class initializer
Added new class Volume needed by the PlacesModel and based on PlacesItem
Removed wasteful else statement
Code cleaned as Qt_Coding_Style expects

For more information consult : http://qt-project.org/wiki/Qt_Coding_Style
Updated CMakeLists for new Mount class
Added new class Mount

This class is needed for PlacesModel and it is based on PlacesItem
This class uses Kommodity/GIO/Mount which is based on GMount
Please consult: https://developer.gnome.org/gio/unstable/GMount.html
CMakeLists updated for new class Action

The related files are action.cpp and action.h
Now PlacesModel is based on QObject
Added new protected method itemFromPath()

With this method we can retrieve a PlacesItem giving its URL