Formatting changes to documentation.
Updating URLs in copyright statements.
Fixes to printTree, and minor changes to plotTree and expandTree.
Formatting changes to sortConditions, splitTree, and toAnon.
Formatting changes to toFirstOrder and toRHS.
Modifying behavior of printTree to accommodate complex numbers.
Modifying behavior of plotTree to accommodate complex numbers.
Formatting changes to tree2infix and treeVar classdef.
Formatting changes to univatiate.
Style changes to tests.
Formatting strings printed via num2str.
Testing the printTree method only by whether it's not crashing.

This is similar to how we test plot methods in general, where the
output has to be inspected by a human eye.
Merge branch 'feature-firstOrder-reform' of ssh://github.com/chebfun/chebfun into fix-chebgui-IVPs

Conflicts:
	@treeVar/splitTree.m
	tests/treeVar/test_toFirstOrder.m