Reimplemented {HASH_TABLE}.is_equal.
1 - compare the basic properties: count, object_comparison, has_default, ...
2 - compare items, go for all the items in the current hash_table and for each
of those, query if the item is present in the other table and if so, compare
them using `object comparisons' or not (depending on the setting).

Redefine {STRING_TABLE}.is_equal taking `is_case_sensitive' into account.

review#9099006

git-svn-id: https://freeelks.svn.sourceforge.net/svnroot/freeelks/trunk@686 6d4a7a74-6026-0410-acef-abb7cea3cd6d