doc/man: follow man-pages(7) for section names/order and for "SEE ALSO"

Changes, following the "Sections within a manual page" section of
man-pages(7):

* Rename the "ENVIRONMENT VARIABLES" section to "ENVIRONMENT".

* Rename the "COPYRIGHTS" section to "COPYRIGHT".

* Move the "EXIT STATUS" section immediately after the "OPTIONS"
  section.

* Remove the "BUGS" section.

  Such a section indicates known bugs (why would you ever have such
  a section anyway?).

  The "RESOURCES" section now contains the URL of our bug tracker.

* Sort the manual pages by section, and then by name in the "SEE ALSO"
  section.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3d91073ec876efd98dcc723ddf40272c814663dd