Remove stream locking from within io.
Default to unlocked streams.
Remove stream-lock: #f now that streams are unlocked.
Make format-out, force-out thread safe.

As requested in http://bugzilla.opendylan.org/show_bug.cgi?id=4004.
Update release notes for change to stream locking.
[doc,format-out] Update format-out module docs.
[docs,streams] Remove bad usage of with-stream-locked.
Clean up whitespace.
Don't lock stream during format().

This shouldn't be necessary when the application is locking correctly.
Don't lock stream during print().

The application should be handling this as well if the stream is
shared between threads.
Seal lock/unlock-stream where possible.

Add sealed domains for lock-stream and unlock-stream on
<byte-string-stream>, <unicode-string-stream>, and
<simple-wrapper-stream>.
[doc,streams] Document locking management methods.
[crt] Use built-ins for counting leading/trailing zeros.

Fixes #411.
Merge pull request #621 from dylan-lang/stream-locking-changes

Stream locking changes
Merge pull request #623 from dylan-lang/builtin-zeros

[crt] Use built-ins for counting leading/trailing zeros.
Remove outdated release note.
Formatting fixes to thread docs.
[doc,threads] Clean up dynamic-bind docs.
byte-storage-address, byte-storage-offset-address.

These methods are for passing the address of byte storage
data to the C-FFI.
[network] Use byte-storage-offset-address, remove buffer-offset.