Adding "eups distrib install --onlydepend" option.

This will allow developers to automatically install dependencies for a given
package, before running "setup -r ." in the git repos of that package.

Blank lines were also removed, please use :
git diff --ignore-space-change
to check the updated code.
Merge pull request #19 from fjammes/u/fjammes/DM-930

U/fjammes/dm 930 (eups distrib install --onlydepend)