A while back, Django Evolution introduced AlterTableSQLResult, which

worked with the mutation optimizer to reduce the number of ALTER TABLE

statements required for traditional databases when applying several

evolutions at once. That didn't work with SQLite, though, since SQLite

required a full table rebuild to make most changes.
This change enables these optimized operations through a new

SQLiteAlterTableSQLResult, which is a specialization of

AlterTableSQLResult that supports its own internal operations for

adding/deleting/renaming/changing columns, setting up state that's used

to construct the destination table when rebuilding.
That reduces the number of table rebuilds significantly, making it less

likely that something can go wrong and speeding up a chain of

evolutions.

Unit tests passed on all supported versions of Django, all databases,

and with SQLite 3.24.0 and 3.28.0 (which both handle table alterations

in subtly different ways).