We have no Application#usage method, so I've modified the help task to print the usage string.
We have no Application#usage method, so I've modified the help task to print the usage string.

git-svn-id: f481de8ecb0d1e2ade8c586a5c716a32a1f3e8c1@706505 13f79535-47bb-0310-9956-ffa450edef68

ittayd/buildr,mariusk/buildr-kawa,atoulme/buildr,mariusk/buildr-kawa,stewi2/buildr,liamchristopher/buildr,stewi2/buildr,liamchristopher/buildr,liamchristopher/buildr,atoulme/buildr,liamchristopher/buildr,ittayd/buildr,jpcaruana/buildr,apache/buildr,apache/buildr,jpcaruana/buildr,assaf/buildr,assaf/buildr,apache/buildr,stewi2/buildr,jpcaruana/buildr,apache/buildr,assaf/buildr,atoulme/buildr,stewi2/buildr,jpcaruana/buildr,mariusk/buildr-kawa,ittayd/buildr