changing sindex perfmons to not collide with primary key
Missing default values

Review 1631 by @larkost
Merge branch 'v1.13.x' into sam_2537
Merge branch 'v1.13.x' into sam_2537
Merge branch 'sam_2537' into sam_2572
Moved some more serialization implementations to .cc files.
Moved metadata serializations to {branch|query}/metadata.cc.