graphlog: split the actual DAG grapher out into a separate method
This allows extensions like pbranch to use asciigraph() to graph dependencies
for patch branches, but could be used for basically any DAG.
#!/bin/shhg initecho This is file a1 > ahg add ahg commit -m "commit #0" -d "1000000 0"touch bhg add brm bhg commit -A -m"comment #1" -d "1000000 0"