[sqlite] temp_store_directory issue with SQLite 3.5.9

Hello, We came across an issue last week with SQLite 3.5.9 on Windows. A program stopped working on Windows when we upgraded from SQLite 3.4.1 to SQLite 3.5.9. It turned out that the cause was that SQLite 3.5.9 (and perhaps SQLite 3.5.x in general) was not fully honoring the

[sqlite] temp_store_directory

Shouldn't temp_store_directory be private to a sqlite3 structure? Currently it is global (in os_*.c), so setting a value through the pragma affects to all currently opened sqlite connections within the process which may be undesirable. I guess the basic idea is to keep as minimum global