Allow Label to wrap at specified characters

This commit provides the option to specify additional break characters.
ParticleEditor: relative path for emitter's image

If image for emitter is located in the same directory as effect file, or in a subdirectory, then path to this image will be saved as relative to the effect file
Check isBreakChar in getWrappedBounds
Merge pull request #2492 from jpilfold/master

Allow Label to wrap at hyphens
Merge pull request #2679 from alex-dorokhov/particle-editor-relative-path

ParticleEditor: relative path for emitter's image
convert touch to root-local coordinates
Merge pull request #2680 from vmilea/root_transform

Wrong stage-to-local transform when the root is not identity
MeshBuilder: don't default to GL_POINTS (0), add end(Mesh) method (see #2156) as well as getNumVertices()/getNumIndices(), run formatter
Merge branch 'master' of https://github.com/libgdx/libgdx
Update CHANGES
MeshBuilder: move vertex transformation (position, normal, color and UV) to the addVertex method so it is applied to all added vertices (required for separation of concerns)