HPCC-8992 - Various problems in key sampling used by merge

1) split() caused a filepos to be lost - it was added before
split and key row after

The effect of this was a array.isItem assert - and the
cause of HPCC-8992 report.

2) the sampling (index%divisor stuff) was basically broken

It would have meant the partitioning would have skewed
toward the end of the set being sampled.

3) expandfpos was adding an extra erroneous filepos when it
initialized (had <= in loop when should have been <).

I suspect this would have caused problems if the 1st row of the
sample were fetched.. (it would probably serialize wrong row)

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>
HPCC-9026 Pull distributor restart issues

Effects Distribute Merge and Global Hash Aggregate inside LOOP

Signed-off-by: Jake Smith <jake.smith@lexisnexis.com>
Ensure no overflow when calculating fpos
Merge pull request #4162 from jakesmith/hpcc-8992

HPCC-8992 - Various problems in key sampling used by merge

Reviewed-By: Gavin Halliday <gavin.halliday@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>
Merge pull request #4163 from jakesmith/hpcc-9026

HPCC-9026 Pull distributor restart issues

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>
HPCC-9015 Restore previous ROLLUP semantics

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
HPCC-9014 Roxie Manual Correction

Fix HPCC-9014 Roxie Manual Correction
Correct couple instances of incorrect
command line parameter, change package
to packagemap.

Signed-off-by: g-pan <greg.panagiotatos@lexisnexis.com>
Merge pull request #4170 from g-pan/H9014

HPCC-9014 Roxie Manual Correction

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>
Split off 3.10.6

3.10.6 was branched from 3.10.4 rather than candidate-3.10.x in order to
provide a single fix for the ROLLUP semantics change issue.

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>
Merge pull request #4164 from ghalliday/issue9015a

HPCC-9015 Restore previous ROLLUP semantics

Reviewed-By: Jake Smith <jake.smith@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>
Merge remote-tracking branch 'origin/candidate-3.10.x'

Conflicts:
	version.cmake

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>