util.sqlite3: Don't cache prepared statements for one-off queries The :execute method is mainly used for one-off queries such as creating tables and indices. There is no need to cache this prepared statement, as those queries are only done on startup. Further, prepared statements can't be reused without being reset, so this was likely broken anyway.

util.sqlite3: Deduplicate query methods There were 3 very similar methods: - :execute() - :execute_query() - :execute_update() The first one returns the prepared statement and is mainly used internally in the library for CREATE statements. The later two only really differ in how the results are returned. Those two are one main method and one small one that only picks out the iterator.

util.sqlite3: Fix indentation

mod_storage_sql: Compose a keyval+ store out of keyval and map store methods Removes the need for the shim in storagemanager. The methods only really access the 'store' property of the first (self) argument, so this is safe.

mod_storage_sql: Add UPSERT support Currently limited to SQLite3 for lack of testing on other databases. Adds a migration to replace the non-UNIQUE prosody_index, renaming it prosody_unique_index since ALTER INDEX does not seem to be portable.

tools: Update imports to use new prosody.* namespace

Merge 0.12->trunk

mod_http: Simplify conversion of Set to Array Avoids the _items semi-private value, that is used everywhere for some reason.

mod_http: Fix error if 'access_control_allow_origins' is set Because it changes the type of the 'opt_origins' variable from util.set to the internal _items table so next time an http app is added an error "attempt to call a nil value (method 'empty')" is triggered. The value is not used anywhere else. Noticed when reviewing uses of the '_items' set property. Not reported by any users, implying this setting is rarely used.

util.array: Expose new() on module table For consistency with other utils. Consistency is good.