Resolves#33.
Fixes the arithmetic comparison in the while loop being
incorrect.
Also, handles the situation in which there are more output
files being specified than scans available, in addition
to the already handled reverse situation.
Without doing so if the device includes a semicolon the following happens:
% ./scan -x 'brother4:bus7;dev1'
Scanning...
scanadf: open of device brother4:bus7 failed: Invalid argument
./scan: line 248: dev1: command not found
Found no scans.
Can't set multiple traps on the same signal -- ensure that when the
verbose option is set, the regular cleanup is done in addition to the
lockfile cleanup.
* Allow page size and crop to be set
* Add driver-based paper lower edge detection with crop
* Add overscan on page size to allow for cropping larger pages
* Do not default size to Letter if crop is specified
When scanning multiple pages, sometimes it is useful to write out
each page scanned to a separately named file.
The new --outputlist argument allows that mode of operation.
