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 zeros[shape] and changed I to identity[d]

  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 identity matrix support (still needs codegen support)

  Added lerp as an overloaded function

added a once-differentiable tent kernel called c1tent

  Adding support for vector normalize

  Catmull-Rom is C1 (not C2)

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

  Working on support for sequences

  Added support for cross product

  Added evals, evecs, outer, and trace to Basis

  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

  Renamed internal variable input to optInput and added input variable.

  Simplified AST code now uses default input values when no input is given.

  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

  Bug fixes

  Fixed some bugs in the basis

  Working on typechecker

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

  Working on typechecker

  More work on the typechecker

  Working on typechecker

  Working on typechecker