Added a molecule model class

Adds a simple model to contain molecules for the application, with
simple ownership semantics.

Change-Id: Ie542e768da275a6b1b7785fb08ba490d1ad3f3c0
Use the file name as a fallback if no name is set

This matches the GUI default style, and makes it easier to navigate
the list of loaded molecules.

Change-Id: Iec076c00f03a945f612706692733eb669b702c3d
Added translation for Untitled string

Change-Id: Ia5545607b9c4217446718b7d5f394e7415bad17d
Make is easier to prefer a file format prefix

Setting format prefix to "Avogadro:" will prefer Avogadro formats,
but still offer resolution if more than one format exists in that
prefix.

Change-Id: I40ff270a9fe3264e310720f3d5bede600c71fbd7
Adding multi view widget with needed infrastructure

This is to replace the main widget in more advanced applications
where they wish to use multiple view widgets with splits.

Change-Id: I65a9989a46871624aba9d6a3771786a406a13a5a
Added a couple more extensions used for Molden files

Change-Id: I2228cd880005b55a894233252cd616f79d282d9a
Work with older Qt 5, fix adding with a widget

The replaceWidget methods were only introduced in Qt 5.2, replace them
with remove and add widget calls. Fix the logic if a widget is added to
the multiview.

Change-Id: Ib4ec559f828b0a9ed8ef767ad6f5b1688b069432
Made the filter a member, also install on added widgets

We just need one filter, but we must ensure the filter is installed
for all widgets (not just those created by the factory).

Change-Id: I35019b10807ded26b363d66c489053515acde96a
Eat the first event when switching widgets

Fixed the activeWidget member function, and eat the first mouse
press event when changing active widgets.

Change-Id: If6a1a80a98cd5eb56c8683aa6a3e0614fe1336fa
Use updateGL rather than update in the GLWidget

This is preferred, and was causing issues with the Intel driver on
Ubuntu 14.04. Also create a dummy molecule so that things like the
overlay axes can be rendered correctly. This is a little hackish, we
should probably improve the API for visualizations independent of the
molecule.

Change-Id: Ia95cf1a6b19a5607c46b1a23f484d015ddaf6be2
Distribute the space more evenly in new splits

Change-Id: I1c9995229e986df90e8159832250a410e1196a5c
Minor fix to the build system

Change-Id: I241a84aa69514040bf639d3209af0c333f5b35dd
Making adjustments to use the RWMolecule

Create a new widget, adapt the tool API, modify some of the tools.

Change-Id: I9f1fc1118499d699f6cb55a88d72e41504be8b68
WIP: Adding a vtkGLWidget

Change-Id: I84e6fc92551af67ede86fb45245a1f812d294d90
Working on that VTK widget!!!

Change-Id: Ie80bb7c018cda4bc7ac327f74c19556a276ecac3
More work on the VTK render widget

Change-Id: If3edab08b3b5075d903e7f6ce4eeca7b6fe2d0f4
Added cubes to molecule, visualize them in VTK widget

Proof of concept right now, very fragile, but it shows the basic
functionality off very well. Volume rendering of a molecular
orbital in the integrated multi-widget views.

Change-Id: I54296307a8d07963379a76f985d550dd2d94af21
The actor doesn't own/initialize a scene

Change-Id: I664d6bbd8ede96e8a806b0acf75c023d019004b0
Added ability to close/remove views

Change-Id: Id1f540e432ff83acace2e2e1d4681edaee54f686
Switch to use QVTKWidget2 for our VTK widget

This is derived from QGLWidget, and so will share the same method of
context creation, etc. Hopefully avoiding some unusual bugs I have
seen that may be related to the use of different APIs for creating
the OpenGL rendering context.

Change-Id: Ia966a66ee54723221f05ff6988afc3aaf1de0d16