* maint-20:
  Updated OTP version
  Update release notes
  Update version numbers
  erts: Add system_flags(erts_alloc,"+M?sbct *")
  erts: Add age order first fit allocator strategies
  erts: Refactor erl_ao_firstfit_alloc
  erts: Add migration options "acnl" and "acfml"
  kernel: Add os:cmd/2 with max_size option
  erts: Add more stats for mbcs_pool
  erts: Fix alloc_SUITE:migration
  stdlib: Make ets_SUITE memory check try again
  erts: Improve carrier pool search
  erts: Improve alloc_SUITE:migration
  erts: Refactor carrier dealloc migration

fmt_double() may write up to 8 characters into its format_str[]
buffer, which however only has room for 7 characters.

This case could be triggered by a call to erts_printf_format() with
any floating-point format that also includes #, and + or a space,
which may be uncommon, but a nif or driver could issue it.

into 'sverker/maint-20/alloc-n-migration/ERIERL-88'

OTP-14915
OTP-14916
OTP-14917
OTP-14918

into 'sverker/maint-19/alloc-n-migration/ERIERL-88'

to change sbct limit in runtime for chosen allocator type.

With great power comes great responsibility.

ageffcaoff: Age First Fit Carrier, Address Order First Fit (within carrier)
ageffcbf  : Age First Fit Carrier, Best Fit (within carrier)
ageffcaobf: Age First Fit Carrier, Address Order Best Fit (within carrier)

Prefer old carriers, the older the better.

In preparation for carrier age order.

Change 'flavor' to 'blk_order' and 'crr_order'.

acnl:  Abandon Carrier Nr Limit
acfml: Abandon Carrier Free block Min Limit