add distance scalar function
support distance function in where clause
use order by symbols instead of references in SearchNode/Task
support distance function in the order by clause
add the within scalar function
support within function in the where clause
add sys.cluster.master_node expression
Merge pull request #899 from crate/l/sys.cluster.master_node

add sys.cluster.master_node expression
geo distance: add a note about the precision difference

between indexed value and calculated value
Merge pull request #902 from crate/geo

add distance and within geo functions
added parser support for insert from subquery
implemented insert by query analysis
implemented internal-only ``cast`` function
added parser support for insert from subquery
added implicit type casting on insert with subselect
implemented insert by query analysis
insert by query plan WIP
fix clusteredByColumn serialization in AbstractIndexWriterProjection
issue inserts on shard for insert-by-query without limit

- forbid insert by query with limit/offset or order by
Merge pull request #893 from crate/m/insert-by-query-plan

implemented insert-by-query plan