Start splitting "normalize" & "simplify" concepts
Merge branch 'master' into normalize
Merge branch 'master' into normalize

Conflicts:
	lib/Math/Symbolic/Operation.pm6
Add timing information to dev script
Note a precomp bug :P
More ::Tree methods, and Numeric for operations

Constructors: new-chain, new-op, new-sym, new-val
Accessors: get, child, chain
Mutators: set, swap
Bugfix
Begin solving for multiple instances of a variable

And various other changes
Merge branch 'master' into poly

Conflicts:
	lib/Math/Symbolic.pm6
Merge branch 'master' into poly
Separate constant folding into .fold()
Bugfix
Bugfix
Start adding ±
Support solving for multiple instances of a symbol

Also fixes some bugs and removes some cruft
Parsing bugfixes
Auto-simplification adjustment
Simplify if no other actions are taken
A few README updates, more to come