Per review by Serg, include start row with new line.
We are hoping we haven't annoyed people that prefered the old
way.
Adding an option for new lines seems like over-engineering in advance.
So if there are complaints, let them be known (JIRA), and we'll add
this under an option.
Test cases updated.
Based on Aleksey Midenkov's patch
mysqldump changes:
* --as-of option specifies historical point;
* query forging protection for --as-of parameter.
system versioned tables are detected by querying I_S.TABLES:
* it transfers much less data when the full table definition is not needed
* it does not give false positives on x TEXT DEFAULT 'WITH SYSTEM VERSIONING'
