Added support for converting links.
upload-to-picasa now accepts --dir and --album

- the parameter --album defaults to album "<month name> <year>"

- the parameter --dir defaults to ~/pictures/<year>/<year>-<month>

- added a few debug statements, activated with the new --verbose

- Put everything into a main method
  this made it possible to add local scope on more variables.

- Added debug() to indispensable.sh
  if a callee sets verbose=1, then all calls to debug() will be
  outputted.

- Added --help

- Added a [debug] label to the debug statements