git-bs: Add "" to the cd command to cope with bloody whitespace

2c1bbd9e-2df8-11e4-badc-c80aa9e67bbd
$ std -l perl dostime

da1d60fc-2e9b-11e4-aaaa-c80aa9e67bbd
dostime works, changes file timestamps from odd to even seconds

Files or directories can be specified on the command line and/or be read
from stdin.

1782c81a-2ea1-11e4-b499-c80aa9e67bbd
dostime: Add -z/--zero option

db84d82a-2ea1-11e4-8213-c80aa9e67bbd
dostime: Don't output messages unless -v/--verbose is specified

That's the Unix way, silence is golden.

157d8290-2ea5-11e4-9d59-c80aa9e67bbd
Merge branch 'add_dostime'

* add_dostime:
  dostime: Don't output messages unless -v/--verbose is specified
  dostime: Add -z/--zero option
  dostime works, changes file timestamps from odd to even seconds
  $ std -l perl dostime

db33323c-2ea5-11e4-b96f-c80aa9e67bbd