Improper error numbers returned on exit

Nutch does not obey standard command line error numbers which can make it difficult to script around commands.

Both of the below should have exited with an error number larger than 0 causing the shell script to enter into the 'Failed' case.

bash-3.00$ /opt/nutch/bin/nutch updatedb && echo "==>Success" || echo "==>Failed"
Usage: <crawldb> <segment>
==>Success

bash-3.00$ /opt/nutch/bin/nutch readdb && echo "==>Success" || echo "==>Failed"
Usage: CrawlDbReader <crawldb> (-stats | -dump <out_dir> | -url <url>)
<crawldb> directory name where crawldb is located
-stats print overall statistics to System.out
-dump <out_dir> dump the whole db to a text file in <out_dir>
-url <url> print information on <url> to System.out
==>Success

Note that the nutch shell script functions as expected:

bash-3.00$ /opt/nutch/bin/nutch && echo "==>Success" || echo "==>Failed"
Usage: nutch COMMAND
where COMMAND is one of:
crawl one-step crawler for intranets
readdb read / dump crawl db
readlinkdb read / dump link db
admin database administration, including creation
inject inject new urls into the database
generate generate new segments to fetch
fetch fetch a segment's pages
parse parse a segment's pages
updatedb update crawl db from segments after fetching
invertlinks create a linkdb from parsed segments
index run the indexer on parsed segments and linkdb
merge merge several segment indexes
dedup remove duplicates from a set of segment indexes
server run a search server
namenode run the NDFS namenode
datanode run an NDFS datanode
ndfs run an NDFS admin client
jobtracker run the MapReduce job Tracker node
tasktracker run a MapReduce task Tracker node
job manipulate MapReduce jobs
or
CLASSNAME run the class named CLASSNAME
Most commands print help when invoked w/o parameters.
==>Failed