Fixed generating sql for relation (fks) and making relation name
Fixed generating foreign key constraints, fixed `coffee:watch` task

Foreign key on composite key cant be defined for each key separately but
have to be defined for all keys (of one relation) at once. Fixed list
of files to watch for `watch:coffee` task.
Fixed making of unique constraint name

Constraint name is unique at one `generate` proccess.
Updated Readme and changed version to 0.4.0

Added new known issues, marked as a resolved some issues.