Add inet overlap selectivity functions.
Remove the network_adjacent_selectivity function.
Rename inet overlap selectivity functions.
Change OID for inetoverlapsel function.
Add description to inetoverlapsel function.
Fix compiler warnings on the inet_hist_overlap_selectivity function.
Remove new line at of network_selfuncs.c
Fix a comment typo on network_selfuncs.c.
Move and rename DEFAULT_NETWORK_OVERLAP_SEL constant.
Fix the operator typo on the network_selfuncs.c
Change default selectivity for other operators on inetoverlapsel.
Support remaining operators with inetoverlapsel.
Generalize names of the selectivity functions.
Return the default when histogram does not exists.
Improve the formula for partial bucket match.
Update the copyright year on network_selfuncs.c.