PerconaFormattedSqlChangeLogParser drops preconditions

[westse]

PerconaFormattedSqlChangeLogParser.parse() first delegates to the default FormattedSqlChangeLogParser.parse() (see here) to produce a list of ChangeSets, which are then translated to a new list of Percona ChangeSets. However, any ChangeSet preconditions are lost in translation (i.e., ChangeSet.setPreconditions() is never called).