improve test display, preserve artifacts

- when tests fail, store artifacts from initial run in failed-tests.tar
- store the original test summary output
- after retry, display both the original and the new test summary
- tweak echo_i and cat_i functions to get output spacing and colors right
39 jobs for !1428 with each-test-retry in 11 minutes and 51 seconds (queued for 4 seconds)
latest detached
Status Job ID Name Coverage
  Precheck
passed #170077
amd64 linux
🐞:sid:amd64

00:00:37

passed #170076
amd64 linux
misc:sid:amd64

00:00:15

 
  Build
passed #170088
amd64 linux
asan:sid:amd64

00:01:19

passed #170089
amd64 linux
clang:stretch:amd64

00:01:12

passed #170090
i386 linux
clang:stretch:i386

00:01:11

passed #170078
amd64 linux
docs:sid:amd64

00:00:44

passed #170087
amd64 linux
gcc:bionic:amd64

00:01:53

passed #170079
amd64 linux
gcc:centos6:amd64

00:02:20

passed #170080
amd64 linux
gcc:centos7:amd64

00:01:52

passed #170085
amd64 linux
gcc:fedora29:amd64

00:01:59

passed #170081
amd64 linux
gcc:jessie:amd64

00:01:36

passed #170083
amd64 linux
gcc:sid:amd64

00:02:02

passed #170084
i386 linux
gcc:sid:i386

00:01:53

passed #170082
amd64 linux
gcc:stretch:amd64

00:01:54

passed #170086
amd64 linux
gcc:xenial:amd64

00:01:53

passed #170091
amd64 linux
pkcs11:sid:amd64

00:01:04

 
  Test
passed #170110
amd64 linux
system:asan:sid:amd64

00:07:02

passed #170108
amd64 linux
system:gcc:bionic:amd64

00:08:52

passed #170092
amd64 linux
system:gcc:centos6:amd64

00:06:29

passed #170094
amd64 linux
system:gcc:centos7:amd64

00:06:04

passed #170104
amd64 linux
system:gcc:fedora29:amd64

00:07:59

passed #170096
amd64 linux
system:gcc:jessie:amd64

00:06:54

passed #170100
amd64 linux
system:gcc:sid:amd64

00:06:42

passed #170102
i386 linux
system:gcc:sid:i386

00:06:25

passed #170098
amd64 linux
system:gcc:stretch:amd64

00:06:56

passed #170106
amd64 linux
system:gcc:xenial:amd64

00:06:45

passed #170113
amd64 linux
system:pkcs11:sid:amd64

00:06:38

passed #170111
amd64 linux
unit:asan:sid:amd64

00:00:59

passed #170112
amd64 linux
unit:clang:stretch:amd64

00:00:44

passed #170109
amd64 linux
unit:gcc:bionic:amd64

00:00:49

passed #170093
amd64 linux
unit:gcc:centos6:amd64

00:00:43

passed #170095
amd64 linux
unit:gcc:centos7:amd64

00:00:54

passed #170105
amd64 linux
unit:gcc:fedora29:amd64

00:00:54

passed #170097
amd64 linux
unit:gcc:jessie:amd64

00:00:41

passed #170101
amd64 linux
unit:gcc:sid:amd64

00:00:49

passed #170103
i386 linux
unit:gcc:sid:i386

00:00:43

passed #170099
amd64 linux
unit:gcc:stretch:amd64

00:00:44

passed #170107
amd64 linux
unit:gcc:xenial:amd64

00:02:03

passed #170114
amd64 linux
unit:pkcs11:sid:amd64

00:01:55