1] datamodel.js: For collection type added check before adding model into "changed" list instead of adding it blindly.
2] Type casting from str to int of column properties like attlen, attpricision.
3] Added missing data formating when adding new column to existing table (from table edit mode).
4] Added more validation for Foreign key constraint.
5] Column.js: Column grid (in table edit mode) show proper disabled color for disabled cell when grid renders.
6] All constraints and index js added idattribute to distinguish which s/constraint or s/index is updated on server side.
7] Column update.sql: Fixed sql when altering column data type. The issue was when we alter data type from which has length and precision to data type which don't have these properties and vice versa.
For e.g. alter data type numeric(10,12) to real (and vice versa)
