Added lerp as an overloaded function

  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

  Fixed bug in the C code that gets generated for subscripting vectors

  The C-target now compiles and links the generated C code

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

  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

  Bug fix: get printing format right for vectors

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

  Add cast to generated code to avoid warning message

  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

  Bug fix: the update function was cast to the wrong type

  Fix conversions from float vector to integer vectors

  Fixed bug in code generation for inside test

  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.

  Working on C target and code generation

  Working on code generation

  Working on code generation

  Working on code generation

  Split runtime names and C target types into their own modules.

  Added "allowedInline" function

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

  Working on code generation

  Working on code generation

  Debugging code generation

  Working on code generation

  Working on code generation

  Working on code generation

  More work on code generation

  Working on code generation

  Add codegen hook into driver

  Working on code generation

  Adding some info about x86 intrinsics

  Working on code generation

  Working on code generation

  Creating a branch to explore a pure CFG IL

  Beginnings of code generation infrastructure