Fix zooming in histogram

Fixes #416
Fix Linux README

.. to refer to /etc/udev not /dev/udev
Fix date selection in Tile Mode

Fixes #424.
ISODate format for UTC date end by "Z"

fixes #419
Blank state

Add a blank state for analysis window
Temporary - remove missing images from qrc file
Add images for BlankStatePages
add images back to qrc file
Blank state train view action

Changed the second action to search for videos and workouts
rather than import. It makes more sense to setup the library
rather than import a single file.

We still need to change the conditions for the train view blank
state to no devices or no videos/workouts.
Add ErgDB to train view blank state

Allow the user to download workouts as well as
scan disk for workouts (they are not likely to
have any workouts of their own).
Initial v3 German Translation

First translated texts.
Blank state for train view

Only show blank state for train view when we have
no devices configured -or- there are no workouts
imported into the library.
No chart menu in blank state
Linux fixup for BlankState

Nothing major, just setting no focus on buttons since
it gives them a salmon pink color, which is pretty nasty
on the 'img' button.

Did I mention that I love this new feature?
UI Nits: Choose Athlete Dialog Buttons

.. order of New, Cancel, Open and a bit of stretch
to stop ugly elongated buttons.
UI Nits: Cosmetic gui updates

- searchbox border
- LTM controls - make search box expand
- Histogram controls - make slider expand
UI Nits: Sensible defaults for screen/font size

Set the default size of fonts and screens based upon the
screen size we're running on.

We may need to think about retrospectively adjusting the
font size for users that have not realised they can change
from the defaults (which may not be valid for their hardware).
Fix conflict with Qwtplot3d

The struct Appearance conflicts with a class
in the QWT3D namespace. So renamed it. Fixes
a compile time error.
UI Nits: BlankState cosmetics

Just wordwrap the labels gives more screen estate to
the right side image making it less likely to be out
of proportion with the text size.

Also changed disc to disk in one of the narrative
texts. Maybe its a 'British English' thing tho ;)