added first draft of reuslt2
added squashed
makes more args ignorable
added getconn and putconn
renamed execute
added load_cursor and load_rows
renamed some args
renamed do
added msg
refined the classmethods
sep the methods
Merge branch 'dev' into rewriting-result
finished a the draft of rewriting
added simple tests of new API
rename sections
print the result (cursor) out
added dry_run mechanism
just print it
set flags dump_sql and dry_run
test modifying the identity column