Amici

- fixes MATLAB compilation of models
- adds option to perform steady state sensitivity analysis via FSA
- condition dependent intitial conditions are now newly set after preequilibration is done

- bugfixes for the ExpData interface
- created build configuration that enables debugging of c++ extensions on os x
- fixed python sbml import when stoichiometry is empty

Fixes a couple of bugs just introduced in v0.7.6

Important: **Use AMICI v0.7.7 due to https://github.com/ICB-DCM/AMICI/pull/403/commits/3a495d3db2fdbba70c2b0d52a3d4655c33c817a2**

Bug fixes:
- Python import: Fix log10 issues in observables (382)
- Matlab: Fix broken model compilation (392)
- Fixed simulation for models without observables (390)
- Fixed potential matlab memory leaks (392)

Breaking C++ API changes:
- Revised ExpData interface (388)

Features/enhancements:
- Add computation of residuals, residuals sensitivity, Fisher information matrix (223)
- More efficient conversion of std::vector to numpy ndarray (375)
- Allow specifying timepoints in ExpData (370)

Minor fixes:
- Condition parameters in ExpData now only temporarily override Model parameters (371)
- Ensure non-negative states for Newton solver (378)

Features/enhancements:
- Check SBML model validity (343)
- Allow per-parameter setting of amioptions::pscale from matlab interface (350)
- Documentation

Major fixes:
- Don't compile main.cpp into python model module which broke modules if amici was compiled without libhdf5 (363)

Minor fixes:
- Fix compiler warnings (353)
- Plotting, SBML example mode, ...