…gning the parameter values and the comments; move some parameters to a more convenient place; all optional parameters are commented with their default value; and add 3 missing parameters. Also fix a bug when either "keep identifier case" or "camelcasetosnake" are set to 0

…_parameters() function.

… of all columns, with the SQL-Server and PostgreSQL names of the schemas, tables and columns names. "col_map_file" defines the output file name. No file is produced if the parameter is not set. When "col_map_file_header" is set, a header line is added to the file. "col_map_file_delimiter" defines the field delimiter. The parameter is a string of 1 or several characters, and may be \t, \n or \r. The default is \t. Per a proposal from alchemistmatt. Improved by me.

…n the generated scripts and let PostgreSQL rebuild the name at constraint creation time.

Add support of schema-level comments