Fix ssh doc typos

ssh_rsa changed to 'ssh-rsa' and missing space added.
ssh: Add function ssh:peername/1 with test

OTP-11345, sto575, tsk374
ssh: Add ssh:sockname/1 incl doc and tests

OTP-11345, sto575, tsk374
fix private_key type documentation in ssh_server_key_api
ssh: Remove use of process dictionary

This is step one in in making ssh process structure less complicated.
As an effect I also found other simplifications/clean ups of the code
that could be done.
ssh: Merge connection_manager and connection_handler processes

Also start adding dialyzer specs and removing dead code
ssh: Enhance error handling
ssh: Eliminate test case failure due to timing issues in test case code
ssh: Make inet option configurable and remove ipv6_disabled option
ssh: Simplify handling of connection attributes (e.i. user and sockname)

OTP-11296
ssh: Add option to disallow CLI

OTP-10976
ssh: Quicker shutdown of an ssh dameon

OTP-11339
ssh: Add CLI test case
ssh: Logging fun and document enhancement
ssh: Correct arity in ssh_no_io.erl

Also remove import statement as it makes code less intuitive
ssh: Correct close handling

Commit 68263a48bfbdac4dc219a91f06af3d535d881850 got close handling
slightly wrong, channels did not get their close message.

Commit 32102f1e8225dada7526c9bfee6622f9026ba4cd did not work as expected
Merge branch 'ia/ssh/no_io/OTP-11490' into maint

* ia/ssh/no_io/OTP-11490:
  ssh: Correct arity in ssh_no_io.erl
ssh: Fix long cli delays. (Part of OTP-11339, OTP-10953)

A step in fixing the tickets.
Prepare release