# Conflicts:
#	doc/examples/pyplots/ensemble_results.py

Replace orifice_vs_pump_openmodelica.PNG extension with .png

See merge request !10

Improve examples

See merge request !8

We should not go into detail about the installation instructions of
JModelica, but refer to their own instructions instead. Should the user
want to install in a virtual environment, the installation of JModelica's
dependencies using pip would be part of JModelica's installation process
(i.e. not RTC-Tools's installation process).

Removed the related virtual environment lines, replacing them with a
general recommendation.

__init__.py:  Change warning when casadi could not be imported to reflect the resulting runtime issues.

Introduce OptimizationProblem.der() method, yielding time-independent derivative symbols for use in path constraints.

goals of the same class (but acting on different variables) can co-exist within the same optimization problem.

# Conflicts:
#	rtctools/optimization/collocated_integrated_optimization_problem.pyx

CollocatedIntegratedOptimizationProblem.der():  Try to use history when computing derivative at t0, returning 0 if the history if not available.

Also corrected an issue where in states_in, der, and integral, the t0 point was counted twice if a history was available.