fix error when deepcopying functions in planner

with immutable argument lists
and providing a proper error trace for UnsupportedOperationExceptions
fix: always return rowcount, even when it's not ascertenaible.
In this cases -1 is returned.
fix arithmetic functions for all numeric datatypes
apply proper validation to datatype conversion of numeric types
Merge pull request #1001 from crate/m/arithmetic_fixes

M/arithmetic fixes
update changes
fix: synopsis of COPY TO used a misleading syntax
Merge pull request #1011 from crate/l/copy-to-fix-docs

fix: synopsis of COPY TO used a misleading syntax
travis-ci: reduce logging, use 'quiet'
Merge pull request #1013 from crate/l/reduce-travis-ci-logging

travis-ci: reduce logging, use 'quiet'
tests: reduce logging
Merge pull request #1014 from crate/l/tests-reduce-logging

tests: reduce logging
support setting custom blob data location globally via config
added docu for supporting custom blob data location
support setting blobs data path per table
renamed global blobs path config setting
renamed per table blobs path setting