Myokit

- Added support for PyQt5.

- The IDE now has a model navigator, that displays the model components alphabetically and lets you navigate large models more easily.
- Fixed a bug in the implementation of `DataBlock1d.grid()`, and updated its documentation: this method returns coordinates for squares where each square represents a data point.
See the [Stewart 2009 OpenCL example](http://myokit.org/examples/#stewart-2009) for an example of its use.
- Added a second method `DataBlock1d.image_grid()` that returns coordinates for points where each point in space represents a data point.
- Fixed bug with Ctrl+Shift+Home in IDE.
- Various small bugfixes in IDE.
- Updated installation instructions on website.

- Fixed bug (with new numpy) in `DataLog.split_periodic`.
- Fixed warnings in GDE.
- Fixed issue with pyside/pyqt difference.

- Updated documentation and examples.
- Added extra callback option to pso for detailed feedback.
- Updated default search paths for Sundials headers and libraries.

- Small bugfix to IDE.
- Added `pre()` method to Markov simulations (`AnalyticalSimulation` and `DiscreteSimulation`).
- Fixed a bug in `lib.markov.AnalyticalSimulation.run` when `log_interval >= duration`.
- IDE now shows exact location of recent files in status bar.
- Fixed bug in `SymPyExpressionWriter.eq()` and renamed classes to use SymPy with capital P.

- Updated documentation.
- Fixed opencl issue.