app: Remove 'New' entry from global menu

The 'New' operation is context-sensitive and therefore does not belong
here.

https://bugzilla.gnome.org/show_bug.cgi?id=729259
app-window: Don't auto-fullscreen boxes on launch

https://bugzilla.gnome.org/show_bug.cgi?id=729168
[l10n] Updated Catalan (Valencian) translation
User docs: removed undesired whitespace
Added Brazilian Portuguese translation for help
Updated Spanish translation
Updated German translation (Bug #729697)
app: Create qemu session source file if its empty

Instead of only creating qemu session source file if it doesn't exist,
also check if its empty and create it if thats the case.

This fixes a crash that can happen if Boxes crashed on a previous run
between the time the file is created and copied.

https://bugzilla.gnome.org/show_bug.cgi?id=730022
Fix French help translation
vm-creator: Ensure VM name is <= 15 characters long

Commit 4dd0b75 put variant id into the VM names (and therefore
hostnames) to make it more likely to assign a meaningful name to VMs but
it also broke express installation for OSs with variants name that are
long and have very strict restrictions on number of characters in
hostnames, e.g win7 professional.

This patch fixes express installation of such OSes by ensuring that VM
name is not longer than 15 characters.
Updated Hebrew translation
Updated Greek translation
spice-display: PROPERTIES shouldn't unset resize-guest

Don't unset 'resize-guest' property of Spice.Display when going to
properties view as its not just redundant but also makes the display
grow or shrink to fit guest resolution, which could easily go beyond the
screen even.

We don't want our window to grow or shrink on its own and especially to
grow beyond the screen. If user was able to set a particular size on the
window, Boxes must not change it on its own as that would be contrary to
what user expects.

This issue didn't realize before commit 1854c96, where we made the
GtkStack holding most of the views, homogenous.

https://bugzilla.gnome.org/show_bug.cgi?id=730158
media-manager: Use correct tracker language property

In the end, it was decided not to make the existing 'nie:language'
property multi-valued but rather introduce a new custom property for
this case, 'osinfo:language'.

This patch also:

* moves the handling of Tracker SPARQL query into a seperate
  module/class, TrackerISOQuery.

* ensures compatibility with older Tracker (that doesn't extract and
  expose the new 'osinfo:language' property) by using different queries,
  depending on whether or not 'osinfo:language' property is known to
  Tracker.

* ensures language info is extracted from media if its available in case
  of older Tracker and therefore ensures that we don't end up using a
  locale that media doesn't support and break express installation.

https://bugzilla.gnome.org/show_bug.cgi?id=729122
Updated Spanish translation
app: Correct the logic of selecting URI

Seems the logic of selecting the argument to Wizard.open_with_uri() was
inverted.
Updated Brazilian Portuguese translation
Updated Brazilian Portuguese translation
wizard: Set UI state on App, not AppWindow

This fixes the issue of Boxes ending up in weird state if passed an
unknown (to Boxes) media through commandline (i-e when review is
skipped).
wizard: Don't try to create the box in two places

'Create' button should only set the appropriate wizard page as the
appropriate page setter already handles the box creation.