Add custom header and tailer to AS 3.15

See merge request !348

chdir was causing long delays, moved the checker from this place to the connectivity check, added keepalive

Changed submission recovery to a better version that keeps in mind the submission time. Changed to sacct since the job could be finished. Also now the jobs are not cancelled if they're not duplicated.

(cherry picked from commit 2cb9eb1b)

(cherry picked from commit 01783457)

(cherry picked from commit 3deeaa46)

(cherry picked from commit 1e31c2c8)

(cherry picked from commit de0535d4)

(cherry picked from commit 05c46817)

(cherry picked from commit 6c6c671b)