kranc2.peg: Escape # symbols in grammar

Needed by newer version of Piraha
Update piraha version
KrancScript.m: Handle new XML format from Piraha
KrancScript.m: Expect name instead of uname when processing parse tree
KrancScript.m: Adapt to "mul" changes in grammar
KrancScript.m: Make processing errors for deqn fatal
KrancScript.m: Add comments
kranc2.peg: Correct parentheses error in dtensor
SimpleWaveScript.kranc: Comment out multi-dimensional differencing operator

This is not yet supported by the processor in KrancScript.m.
Examples: Regenerate SimpleWaveScript
Examples: Regenerate EMScript
Examples: Regenerate WaveCaKernelScript
Examples: Remove spurious empty file SimpleWaveScript2.kranc
Examples: Generate SimpleWaveScriptCaKernel