generic thread pool should always be cached
when using generic thread pool, some elements in the code base rely on the fact that it will always be able to fork it
simplify by directly getting the search TP info
*a*wait...
Add more info to table row size errors.
Add ByteSizeValue to SegmentStats.
Add rest of indices primaries stats.
Add alias sample.
Swap help and headers params.
Add remaining aliases to cat/indices.
Document h/headers switcheroo.
Add total stats to cat/indices.
Add rest of index stats to cat/nodes and cat/shards.

Closes #4607.
Update primaryOrReplica column.
cat stats: remove "total" prefix and shorten "primaries" to "pri"

total is the normal case and primaries just shows up in _cat/indices.
Make partial dates without year to be 1970 based instead of 2000

Fixes #4451

Date fields without date (HH:mm:ss, for example) are parsed as time on Jan 1, 1970 UTC. However, before this change partial dates without year (MMM dd HH:mm:ss, for example) were parsed as as days of they year 2000. This change makes all partial dates to be treated based on year 1970. This is breaking change - before this change "Dec 15, 10:00:00" in most cases was parsed (and indexed) as "2000-12-15T10:00:00Z". After this change, it will be consistently parsed and indexed as  "1970-12-15T10:00:00Z"