Fix for url-quoteing of # in uris

Fix for url-quoting of allowed special characters, including #.

Increase checks on metadata and csv file compatibility in terms of number of columns and virtual columns following non-virtual columns in order.

Fix for not urlquoting for "default" values of virtual columns

The bug where substitutions specified in "default" value of a virtual column were url-quoted, causing for example space characters in a string literal to be converted to "%20", is fixed.

Also, the issue about out variable not initialized is addressed.