Enhance the file filtering capabilities.
We now allow filtering through either pipes or pairs of temporary
files. The latter appear to be mandatory for use on Windows.
#!/bin/shhg initecho This is file a1 > ahg add ahg commit -m "commit #0" -d "0 0"lsecho This is file b1 > bhg add bhg commit -m "commit #1" -d "0 0"hg co 0# B should disappearls