Merge table alters, keep SQL quoted, format SQL

Every table alteration involves: 

1.  creating a new temp table with the modifications
2.  copying all data over from the old table to the temp table
3.  deleting the old table
4.  renaming the temp table to the old table

This is very slow on large databases (such as NN), by merging the alters into one command it will significantly reduce time spent altering tables.