When invoking the various subcommands make sure the path to the executable
is quoted. This allows it to contain spaces.
On Windows quoting the command passed to `system()` or `popen()` is not
enough. The default behavior under windows will strip quotes from the
beginning and end of the command string under certain conditions. For this
reason implement `system()` and `popen()` equivalents that do not suffer
from this.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Lars-Peter Clausen