added literal defaults for table columns.
added postgres constants.
added ConstantTableColumnDefault
added string literal default to LabelValue
added flag to distinguish builtin functions from user defined functions
create uuid generator function.
filter defaults
set uuid generator function as default for id columns.
create audit tables for data tables.
create edge between data table and audit table.
refactored.
create insert audit trigger
create update audit trigger function
create prevent delete trigger function
create triggers
create insert audit trigger
create update audit trigger
craeted prevend truncate trigger function and trigger