fix file opening for some commands on Windows
Using file as opener in debug commands won't work on Windows, as the
index and data files needs to be opened in binary mode.
#!/bin/shmkdir acd ahg initecho foo > bhg add bhg ci -m "b" -d "0 0"chmod -w .hgcd ..hg clone a bcd bhg verifycd ..chmod +w a/.hg # let test clean up