skype: update to 8.73.0.92,

[mobinmob]

• use the rpm as distfile,
  (the deb has changed dir structure and I vastly prefer to handle rpms),
• simplify do_install(),
• add comments on do_install().

General

• This is a new package and it conforms to the quality requirements

Have the results of the proposed changes been tested?

• I use the packages affected by the proposed changes on a regular basis and confirm this PR works for me
• I generally don't use the affected packages but briefly tested this PR

[mobinmob]

• Update to 8.72.0.94.
• Rebase onto master.
• Fix commit message.

[mobinmob]

• Update to 8.73.0.92.
• Rebase on master.