Enlighten

**New Features**
- [Manager.counter()](https://python-enlighten.readthedocs.io/en/stable/api.html#enlighten.Manager.counter) and [Manager.status_bar()](https://python-enlighten.readthedocs.io/en/stable/api.html#enlighten.Manager.counter) now have a ``replace`` keyword argument
- ``replace`` value must be an existing managed counter or status bar
- New counter will assume the position of the counter it replaces
- Old counter will be closed and removed
- Equivalent to setting ``leave=False`` and running ``counter.close`` before adding a new counter

- ``percentage_00`` and ``count_00`` added as ``bar_format`` [formatting fields](https://python-enlighten.readthedocs.io/en/stable/api.html#counter-format) (42)
- Sum of percentages and counts for all subcounters
- Inverse of percentage_0 and count_0

**Changes**
- ``position`` for [Manager.counter()](https://python-enlighten.readthedocs.io/en/stable/api.html#enlighten.Manager.counter) and [Manager.status_bar()](https://python-enlighten.readthedocs.io/en/stable/api.html#enlighten.Manager.counter) must be >= 1
- This was assumed before, but not enforced

**Bugfixes**
- Improved behavior of multicolored bars to avoid partial bars when count is 0 (41)

**Housekeeping**
- Fixed typos
- Minor refactoring

**Changes**
- [Manager()](https://python-enlighten.readthedocs.io/en/stable/api.html#enlighten.Manager) argument, `threaded`, now defaults to True when multiple processes are detected
- Evaluation of [Manager()](https://python-enlighten.readthedocs.io/en/stable/api.html#enlighten.Manager) argument, `threaded`, now deferred until scroll area is set when not set explicitly
- Added FAQ question about reentrant calls

**Housekeeping**
- `blessed.Terminal` subclass removed
- Removed assert statements from code

**Bugfixes**

- Improved write atomicity [ Issue 36 ]
- Improved behavior when multiple processes are writing to the terminal

**New Features**
- Added ``interval``, the inverse of ``rate`` as a built-in [formatting](https://python-enlighten.readthedocs.io/en/stable/api.html#counter-format) field. [ Issue 34 ]
- Added new [``Manager()``](https://python-enlighten.readthedocs.io/en/stable/api.html#enlighten.Manager) argument, ``threaded``, which forces threading behavior when ``True``
- Defaults to ``True`` when multiple threads are detected

**Changes**
- Deferred resize handing introduced in 1.6.2 is now only performed if [``threaded``](https://python-enlighten.readthedocs.io/en/stable/api.html#enlighten.Manager) is ``True`` (default when multiple threads are detected)

**Bugfixes**
- Improved resize handing [ Issue 33 ]

**Housekeeping**
- Add 3.9 support to package metadata
- Minor optimizations

**Changes**
- Output will now be resized on the first write after a resize is detected
- This addresses an issue that can cause threaded programs to crash 28
- Default Unicode are now used when running under Windows Terminal
- Other windows terminals, like CMD, will still default to cp65001 compatible characters

**Bug fixes**'
- Additional stream flushes added to ensure incidental flush aren't relied upon 21
- Updated RPM installation instructions

**Changes**
* Warning is now emitted when a reserved field is passed as a user-defined field
* Drop Python 2.6 support
* Begin testing 3.10-dev

**Bug fixes**
* Preserve max scroll offset when number of status bars decrease (27)
* Minor doc fixes