HPCC-11713 Remove file based environment code (unused since 2010-03-29)

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
HPCC-11713 Convert most connections to /Environment

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
HPCC-11713 Convert some connects to children of environment

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
HPCC-11713 Final set of environment changes

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
HPCC-11713 Remove unused timeout

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
HPCC-11713 Increase timeout and remove need to clone tree

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #6089 from ghalliday/issue11713

HPCC-11713 Change environment access to go through the cache

Reviewed-By: Jake Smith <jake.smith@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>