odd sizing for hash tables.

Came across a few odd things, especially when copy/copy-constructing from other hash tables.

• HashPtrTable copy from HashPtrTable: uses default size, not related to what it is copying
• HashTable from initializer_list uses list size, not 2*list size for its table
• HashSet from HashTable uses number of keys, not the table size.

mentioned in commit 2101691b20250ad6b4a34874b8a19f960366c72c

The HashTable shrink method resizes the table to number of entries. I think that this will potentially provoke many collisions. I don't think it is being used. If isn't being used, I think it should be dropped.

@andy

agreed

mentioned in commit b7c1f28b

mentioned in commit f0ae0275

closed

mentioned in commit 3b95f1e4