This commit marks (hopefully) ever one-parameter constructor as explicit.
It also uses override in (hopefully) all circumstances where a virtual
method is overridden.
There are a very few other minor changes - most of them were necessary
to get everything to compile (like one additional constructor). In one
case I changed an implicit operation to an explicit string conversion -
I think the automatically chosen conversion was much more convoluted.
This took longer than I want to admit but not as long as I feared :)
The main change is that reassembly code (e.g. for TCP) now uses
int64/uint64 (signedness is situational) data types in place of int
types in order to support delivering data to analyzers that pass 2GB
thresholds. There's also changes in logic that accompany the change in
data types, e.g. to fix TCP sequence space arithmetic inconsistencies.
Another significant change is in the Analyzer API: the *Packet and
*Undelivered methods now use a uint64 in place of an int for the
relative sequence space offset parameter.
