Overload the infix convolution operation so that it is commutative.

added c2ctmr kernel, an ostensibly C2 copy of the Catmull-Rom kernel

  Some debugging and added "^" as power operator.

  Adding support for outer product

  Generalized dot product to inner product of tensor types.  Added IL support for
  vector-matrix, matrix-vector, and matrix-matrix multiplications.  Code generation
  and runtime support is still missing.

  Adding support for infix dot and cross-product operators

  Added lerp as an overloaded function

added a once-differentiable tent kernel called c1tent

  Adding support for vector normalize

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

  Added support for cross product

  Added evals, evecs, outer, and trace to Basis

  Made cfg type immutable

  Creating a branch to explore a pure CFG IL

  Added additional operations on fields (F+F, F-F, sF, Fs, F/s)

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

  Simplify basis by removing cruft that is not being used.

  Added infix convolve syntax

  Split function and variable namespaces and add notion of restricted operations
  that cannot appear inside actor or initialization code.

  Added min and max on reals.

  Moving compiler sources into src/compiler

  Fixed some bugs in the basis

  Added new syntax for tensor-value construction and more work on typechecker.

  More work on the typechecker

  Working on typechecker

  Rosking on type checker

  Propoagating changes to meta variables

  Working on Basis

  Added TypeVar module

  Working on typechecking for Diderot

  Starting to work on the basis environment