wltp_db: Freshly rerun with proper class (not forcing class3b to all).

* Also removed 1039 bad vehicle.
wltp_db: Update TESTS for Heinz-results unforced class3b.
wltp_db: HONOR unladen_mass & v_max from Heinz.

* Update wltp_db TESTS.
* log: core: Reduce clutter from too many revolutions :-)
docs: Update CHANGES.

* model: Add ``downscale_factor_thereshold`` in the model.
model: TRY nesting wltc_data() in /params/wltc_data using
jsonschema-refs.

TOO SLOW (0.15sec-->4.13!!)
[ci skip]
model: Nested wltc_data() in /params/wltc_data using
jsonschema-refs.

TOO SLOW (but perfed)
model: TRY PandelVisitor to check if validation speeds-up.
ci: Make README.rst filtering siltent.

Minor prepare CHANGES for release.
pandel: Speed-up 10% PandelVisitor by removing recursive scoping.

* Do not validate model-schema on experiment-executions.  Extremely
slow!
pandel: FIX tests from prev-commit that validates meta-schema with
visitor.
* model, core: Possible to force ``f_downscale``.
* model: Delete forgotten rsults_base().
* ci: Test building in 'pypi' environment.
* ci: TravisCI possible to deploy into PyPi if repo tagged.
* docs: Prepare CHANGES for release.
BUMP VER 0.0.9-alpha-->alpha1

* build: Set default python for eclipse.
Merge branch 'schema_refs'.
Make ver semantic.

* ci: Remove PyPi env - it fails on matplotlib.
FIX version doctest.
ci: Do not deploy into PyPi, so as to PGP-sign the package.
docs: FIX broken symlink docs/docs from schema-refs branch.
[ci skip]
docs: README: Add pyplot-directive for PMR vs (diff_P & diff_N) in
metrics section.
[ci skip]
docs: metrics: Split engine-speed/power in 2 plots and beaty them.

* ver: bump from 0.0.9-alpha.1-->alpha.2.
* model: Methods for class and part limits, with TCs.
* pandel: Methods to resolve and set json_pointers, with TCs.
metrics: Add Arrows-plot on pmr-->n.

* plots: Move plots into main-code.