Clean up modelines and indentation.

Clean up modelines and indentation.

HT tab stops are set every 8 spaces on UN*X; UN*X tools that treat an HT
character as tabbing to 4-space tab stops, or that even are configurable
but *default* to 4-space tab stops (I'm looking at *you*, Xcode!) are
broken.  tab-width: 4, tabstop=4, and tabSize=4 are errors if you ever
expect anybody to look at your file with a UN*X tool, and every text
file will probably be looked at by a UN*X tool at some point, so Don't
Do That.

Adjust indentation to reflect the mode lines.

Change-Id: Icf0831717de10fc615971fa1cf75af2f1ea2d03d
Reviewed-on: https://code.wireshark.org/review/14150
Reviewed-by: Guy Harris <guy@alum.mit.edu>