Added lerp as an overloaded function

  Add Trace to codegen

  Overhaul in the way that the MidIL and LowIL represent tensor types (especially
  for orders > 1).  We still need to deal with the flattening of tensor-value
  construction

  Finish support for normalize

  Added subscript for vectors and code generation for Subscript when argument
  is vector.

  Working on implementation of tensor slices

  Added mechanism for supporting "black box" functions (e.g., sin and sqrt).
  Also added atan2, sqrt, and tan functions to Basis

  Added trace operator for 2x2, 3x3, and 4x4 matrices

  Bugfix: missing code when exit was stabilize/die

  Added support for tracking output state variables through ILs and generating
  a print function in the C target.

  Fixed bug when update always ended in stabilize/die.

  Starting to work on partitioning strand states

  Fix potential type error in generated code

  Bug fix: be more careful about flushing pending code.

  Switch to compiler-generated initially code.

  Working on generating initially code.  Also changed var and exp types in CTarget to
  be datatypes for better typechecking and documentation.

  More work on supporting initially in code generation

  Adding for loops to C code generator

  Added ++ and -- as prefix and postfix operators

  Adding for loops to TreeIL to support initially code generation

  Adding support for initially to IL.  Also factored out more common code from
  high-to-mid and mid-to-low into translate-fn.sml

  Fixed bug in the handling of assignments to literals

  Added missing new lines and function for printing TreeIL statements

  Working on missing pieces of code generation

  Streamlined code for real to int conversions

  Working on code generation

  Working on code generation

  Working on code generation.

  Add decls for local variables

  Working on code generation

  Working on code generation

  Added "allowedInline" function

  Lots of changes to push image info through to the code generator.

  Working on code generation

  Working on code generation

  Added E_Cons support to TreeIL pretty printer

  Fixed issue in low-to-tree conversion when one branch of if ends in die or stabilize

  Debugging code generation

  More work on code generation.  Made sure that the census info is initialized for
  all ILs.

  Working on code generation

  Debugging code generation

  Working on code generation: added printing for TreeIL

  Working on code generation

  Working on code generation

  Working on code generation

  Working on code generation

  Working on code generation

  Working on code generation

  More work on code generation

  Working on code generation

  Working on code generation

  Working on code generation

  Working on code generation

  Working on code gen

  Working on code generation

  Working on code generation

  Working on code generation

  Working on code generation 

  Change "actor" to "strand"

  Creating a branch to explore a pure CFG IL

  Working on codegen

  Working on codegen

  Working on coed generation

  Minor edit

  Working on code generator API

  Upated URL in header to diderot-language.cs.uchicago.edu

  Beginnings of code generation infrastructure