Jiminy-py

The sensors are now updated at the end of the integration steps instead of the beginning, so that the system state is now consistent with sensors data. Moreover, pipeline builder has been reworked more maximum flexibility.

New features:
* [python] Replace 'BaseJiminyController' controller by 'BaseJiminyObserverController' to add dedicated observer support.
* [gym] Add frame stacking pipeline block and wrapper.

Improvements:
* [core] Update sensors data at the end of 'step' for consistency with robot state.
* [gym] Controller/observer blocks must be fully configured at init. Block '_setup' is now called at 'reset'.
* [gym] Take advantage of new dedicated observer.
* [gym] 'get_observation' recursively shadow-copy observation before returning it to avoid altering original data structure.
* [gym] Rework pipeline builder to be more flexible.

Bug fixes:
* [gym] Fix observe/control update period computed at init instead of reset.
* [gym] Update '_action' buffer to match latest 'compute_command' call.

Miscellaneous:
* [core] Add 'PRINT_WARNING' macro, to print debug message when compiling in debug mode only.
* [gym] Rename '*DictRecursive' in '*DictNested' for clarity.

This release greatly improves the compliance with OpenAI Gym API by enforcing complete configuration of the environment at initialization. As a result, it is no longer possible to change environment properties such as the observation and action spaces, but it is still possible to update the load a different robot model as long as it is compatible with those properties. So it should not be limiting fr the vast majority of applications.

New features:
* [gym] Make sure the environment is completely initialized at '__init__', which is expected by OpenAI Gym API.

Improvements:
* [core] Catch some seldom exceptions.
* [core] Enable to call 'initialize' multiple times for 'Engine*'.
* [core] 'isSimulationRunning' is set to True at the end of 'start' instead of the beginning.
* [gym] Force sending zero motor efforts at reset since the initial action is undefined.

Bug fixes:
* [core|python] Several critical bug fixes.
* [gym] Fix base env '_setup' method not called at reset.

Observers and controllers can now be mixed freely, with independent update period.

New features:
* [gym] Add 'PartialFrameStack' wrapper and 'build_wrapper' utility.
* [gym] Add dedicated 'observe_dt' attribute to observer interface.
* [gym] Rework observation block to support multiple update period and more flexible pipeline architecture.

Improvements:
* [core] Enable to access sensors group shared data matrices by reference without copy.
* [core/python] Do not cast-away constness when sharing memory between Eigen Matrix and np.ndarray.
* [python] Handle more C++ exceptions.
* [gym] Refactor 'reset' of gym environment to fix initial state inconsistency and make everything simpler.
* [gym] Factorize pipeline wrappers 'step' method.

Bug fixes:
* [python/viewer] Fix display in Spyder IDE.
* [gym] Fix set seed simulator. Fix cartpole 'compute_command'.
* [gym] Fix 'write_log' missing format.

Miscellaneous:
* [gym] Rename 'gym_jiminy_common' in 'gym_jiminy' for clarity.

This release consists only of bug fixes.

Bug fixes:
- [misc] Fix cmake Python packages installation not overwriting existing install in some cases.
- [misc] Improve re-run-ablility of Pypi wheels generation.
- [misc] Fix windows wheels deployement on Pypi.
- [python] Fix deprecated 'write_log' calls.

Every dependency but Boost.Python is now statically linked. Window wheel now bundles dynamic libraries in the same way Linux wheel does.

Miscellaneous:
* [misc] Use static linkage for every Boost components, except Boost Python.
* [misc] Add auditwheel-like processing to sanitize windows Python wheels.

It is now possible to export/import log files in HDF5 format. [HDF5](https://portal.hdfgroup.org/display/HDF5/Introduction+to+HDF5) is especially well suited for storing log data because it enables to compress and extract each variable individually and only when needed. It also enables to store metadata directly with data, which is very helpful to store information required to reproduce results.

New features:
* [core|python] Add import/export logs to HDF5 format.

Improvements:
* [misc] Improve re-run-ability of automatic build dependencies scripts.

Miscellaneous:
* [misc] Enable optimizations in build dependencies scripts.
* [misc] Disable completely build docs in build dependencies scripts.
* [misc] Disable dev warnings in build dependencies scripts.
* [misc] Quiet Git reset of submodules in build dependencies scripts.
* [misc] Add HDF5 SOUP dependency.
* [gym] Disable flaky Acrobot learning unit test.