This fixes commit 575a5354.

When used within multiple threads, the previous code would raise:

ProgrammingError: SQLite objects created in a thread can only be used in
that same thread. The object was created in thread id XXX and this is
thread id YYY.

Let's find a better fix.

... to facilitate copy and paste in a REPL.

Also, some code refactoring.

Quotes were added in the database.

This fixes commit 3817aa59.

Let's pass the data as function parameters. This greatly simplifies when
using monkey-patching to apply fixers on code that is compiled, for
example. Otherwise, we need to also monkey-patch the code that compile
that code (to change the name).

We can then execute the following query, for example, to find out the
bits of code for which there is no information traced at runtime:

(This is an example for the "division" problem)

SELECT filename
FROM modified
WHERE fixer = "division"
AND filename NOT IN
  (SELECT filename
   FROM division)

The except_clause which are in the "try", "else", or "finally" sections
were detected by mistake.

This is a fixup for commit 3aded8e0.