Fixes two bugs in deserializing DateTime objects from strings.

1) Long-form dates "yyyy-MM-ddTHH:mm:ss.fffffffZ" are now correctedly parsed with Kind=Utc

Previously, only short-form dates (no trailing ".ffff" milliseconds) were parsed as Kind=Utc. Long-form were parsed as Kind=Local

2) Added RepairXsdTimeSeparator() method to work around a bug in System.Data.SQLite v1.0.88, which sometimes uses a space instead of the 'T' separator between the time and date.

Obligatory XKCD reference: http://xkcd.com/1179/