Introduce "BoneWidth" and "Bone Tip Width" parrameters. Add handles for them.
Enable loading for bone files of previous format
Ass "Link to Skeleton" action. Not works (its functionality is copied from "Link to Bone").
Write pseudo-code implementation of "Link to Skeleton" action
Revert "Update "Link to Bone" action"

This reverts commit fa970d93ee3902d9a8474fe03d455b690bc36889.

Conflicts:
	synfig-studio/src/synfigapp/actions/valuedescbonelink.cpp
Revert "Fix ValueNode_BoneLink"

This reverts commit 0861550372405fa8923ae117defd2c51be953f94.

Conflicts:
	synfig-core/src/synfig/valuenode_bonelink.cpp
Revert "Add list of bones into ValueNode_BoneLink"

This reverts commit e3dfa7c35c8f4506c85677a1f28dd050e982a7de.

Conflicts:
	synfig-core/src/synfig/valuenode_bonelink.cpp
	synfig-core/src/synfig/valuenode_bonelink.h
Draft of ValueNode_Bone::have_influence_on()
Draft of Action::ValueDescSkeletonLink
Implementation of Link to skeleton (Bugs!)
Visualize bone width
Fix bone width ducks (rotate 90 deg)
Fix 'link to skeleton' action
Add possibility to load previous format of BoneLink
Use smaller width for bones by default
Add amount parameter for skeleton layer
Fix bug with "Link to Skeleton" action
Add forgotten file to Makefile.am