Revert "F12 offline Freestyle rendering support in Eevee"

This reverts commit 8a7c0abc2d548d88b755a1c712aa06f0ee631076.

F12 offline Freestyle rendering support in Eevee

This patch adds F12 offline Freestyle rendering support to Eevee.

Most functionalities are identical with those found in Cycles.

The only major difference is that the per-view layer "use Freestyle" toggle
option is currently placed in the "Passes" panel of the "View Layers"
properties window instead of a "Layer" panel as in Cycles. Since Freestyle
is a post-processed overlay and not a pass, the present option location is
a compromise. To describe this fact, the per-layer "use Freestyle" option
is in a subsection labeled as "Layer".

Reviewers: fclem, brecht, campbellbarton

Reviewed By: fclem, brecht

Subscribers: dfelinto

Differential Revision: https://developer.blender.org/D3084

Merge branch 'master' into blender2.8

Conflicts:
intern/cycles/blender/addon/ui.py

Fix for missing "Use Freestyle" toggle in the Cycles "Layer" options panel.

Reviewed By: Brecht Van Lommel (brecht), Dalai Felinto (dfelinto)

Differential Revision: https://developer.blender.org/D3048

Freestyle: Unnecessary repeats of Cycles property copying.

As a follow-up to the commit rB354f92a49458795c69f857de927c5b1531cd3618
for fixing Freestyle crash when using Cycles (thanks Brecht for the fix), this revision
applies a related bugfix addressed partly in D3040 (item #2 in the description).

Freestyle: Additional debug info for the render engine used for stroke rendering.

Freestyle: Feature edge selection by nested object groups.

A group of object groups can be formed by means of the dupli_group option in
the Object properties window. The present revision extends the Selection by
Group option in the Freestyle Line Set so as to support not only flat object
groups but also nested groups.

Freestyle: Use of the Fill Range by Selection operator in the mesh edit mode.

This revision extends the functionality of the "Fill Range by Selection" button in
the "Distance from Camera/Object" modifiers so that only selected mesh vertices
in the edit mode are taken into account (instead of considering all vertices when
in the object mode) to compute the min & max distances from the reference.
This will give users much finer control on the range values.

Freestyle: Fix (unreported) wrong distance calculation in the Fill Range by Selection operator.

Distance calculation performed by the "Fill Range by Selection" button of the
"Distance from Camera" color, alpha and thickness modifiers was incorrect,
limiting the usefulness of the functionality.

The problem was that the distance between the camera and individual vertex
locations was calculated in the world space, which was inconsistent with the
distance calculation done by the modifiers in the camera space.

Fix T49479: Freestyle inconsistent line drawing with large geometry dimension.

Ray-plane intersection routine GeomUtils::intersectRayPlane() was used with an
unnormalized direction vector as input.