Fix typo in xseed scripts.
Use argparse in obspy-scan.
Use argparse in obspy-runtests.
Conditional dependency on argparse.
Use argparse in obspy-mopad.

I tested this in general, but not every single option. Note, the gmt
subcommand was broken originally.
Restore deprecated script options, with a warning.

They will produce a UserWarning, but otherwise should work as they did
previously.
Merge branch 'krischer/argparse' into argparse