stdlib: Remove race in ets_SUITE:delete_large_named_table
stdlib: Remove race in ets_SUITE:delete_large_tab
Fix http_request:http_headers/1 to send content-length when length is zero

In R16B01, the http_request:http_headers/1 function removes the content-length
field from the HTTP headers if the content length is zero. This results in
some (perhaps many) HTTP servers rejecting POSTs and PUTs without data with
a 411 status word. From RFC2616, section 14.13: "Any Content-Length greater than
or EQUAL to zero is a valid value".
kernel: Add application:ensure_started/1,2

Similar to application:start/1,2 except it returns 'ok' on already
started applications instead of {'error', {'already_started', ...}}.
kernel: Tests for application:ensure_started/1,2
tests: Refactor away ?line macro in test suite

Refactor away ?line macro in application_SUITE
[debugger] Add an option 'Strings'

A new checkbox has been added. When it is checked, the range set by
the 'erl' flag '+pc' is used for determining when to print lists of
integers as strings. When it is unchecked, integer lists are never
printed as strings.

A minor incompatibility: settings saved by Erlang R16B01
or later cannot be read by Erlang R16B or earlier.
kernel: Document application:ensure_started/1,2
Merge branch 'sverk/test-cuddling' into maint

* sverk/test-cuddling:
  stdlib: Remove race in ets_SUITE:delete_large_tab
  stdlib: Remove race in ets_SUITE:delete_large_named_table
Merge branch 'hb/debugger/strings/OTP-10899' into maint

* hb/debugger/strings/OTP-10899:
  [debugger] Add an option 'Strings'
Added guard for invalid field and values in headers
Merge branch 'maint'

* maint:
  [debugger] Add an option 'Strings'
  stdlib: Remove race in ets_SUITE:delete_large_tab
  stdlib: Remove race in ets_SUITE:delete_large_named_table
Merge branch 'egil/kernel/application-ensure_started/OTP-10910' into maint

* egil/kernel/application-ensure_started/OTP-10910:
  kernel: Document application:ensure_started/1,2
  tests: Refactor away ?line macro in test suite
  kernel: Tests for application:ensure_started/1,2
  kernel: Add application:ensure_started/1,2
Merge branch 'maint'
ssl: Add missing configuration in test case
Merge branch 'ia/ssl/test-maint' into maint

* ia/ssl/test-maint:
  ssl: Add missing configuration in test case
Merge remote branch 'upstream/maint'
Merge branch 'fredrik/inets/header-error' into maint

* fredrik/inets/header-error:
  Added guard for invalid field and values in headers
Merge branch 'maint'
Merge branch 'cm/bug-http-content-length-zero/OTP-10934' into maint

* cm/bug-http-content-length-zero/OTP-10934:
  Fix http_request:http_headers/1 to send content-length when length is zero