Add progress bar for downloads and log levels

[rase-]

• Adds a progress bar for HTTP downloads similar to what master has
• Adds a -v, --verbose option to show Install package@version (disables progress bar)
• Adds a -d, --debug option to show (in addition to the above) the current resolve output

Currently we pass the specified log level to the functions that need it, which isn't "scalable" when more logging is added, so we might want to consider something better suited. Would you rather we look at that right away or rather delay until necessary?

What do you think about the way to specify log level through such command line arguments? To me it's a very appealing approach, because it provides a nice and descriptive way to provide a certain log level. If we end up with something like this, we could document the options along with how they affect log level in -h.

[alexanderGugel]

Loving it. Want to perf test the progress bar before merge into master though :-D