Fix of HEX-1200.

Remote chunks have not updated _vec attribute.
But in this case we can pass length of domains at the beginning of
computation.
RCurl now uses GET to communicate with H2O
Fix for shared variable in VA converter
Fix of constants for Progress.
Comment out over-aggressive assertion showing up for what appears to be valid situations.
(Assertion is doing a variance check.)
summary: fix asserts when column is entirely NA