Provides utility functions for managing uniforms.
src -- An object representing uniform definitions.
Clones the given uniform definitions by performing a deep-copy. That means if
the [page:Uniform.value value] of a uniform refers to an object like a [page:Vector3]
or [page:Texture], the cloned uniform will refer to a new object reference.
uniforms -- An array of objects containing uniform definitions.
Merges the given uniform definitions into a single object. Since the method
internally uses [page:.clone](), it performs a deep-copy when producing the
merged uniform definitions.
[link:https://github.com/mrdoob/three.js/blob/master/src/[path].js src/[path].js]