DOCS-1044 updates to collMod for TTL collections

Signed-off-by: Sam Kleinman <samk@10gen.com>
DOCS-1044 minor cleanup

Signed-off-by: Sam Kleinman <samk@10gen.com>
minor: unix ports less than 1024 require root access, not 1000

Signed-off-by: Sam Kleinman <samk@10gen.com>
Update 2.4-upgrade.txt

Wanted to de-emphasize that all network interruptions required
resyncs, note about --fork from alberto, and minor note about storage
size issues.

Also includes additional edits from Sam Kleinman.

Signed-off-by: Sam Kleinman <samk@10gen.com>