Adding initial url override for bosco bootstrap

From issue #4
Allow custom packages to be brought along and installed

From #3
Adding support for package in batching

From #3
Fixing bactching with custom packages

From #3
Merge branch 'custom-url' into develop
Adding async update of batch results

From #6
Merge branch 'async-batch' into develop
Changing the default download directory

Changing the default download URL from dropbox to osg-xsede.
Adding checking for outdated remote URL

Expanding on #4
Only update the batch file if something changes

Expanding on #6
Updating documentation for remotePackages and Rurl

From #3 and #4
Merge branch 'develop'