[Numpy-discussion] Replace typechars considered harmful

[Sasha]

After a day of debugging I found that convertcode replaced '1' with
'b' in the code which was selecting database columns with names ending
with '1'.  Since it is probably very difficult to automatically
differentiate between '1' used as a typecode and other possible uses,
I suggest to either make "replace typechars" optional, or make it
write verbose message with a few lines of context when it changes the
code.

-- sasha