[chirp_users] New Daily Build

[Build System]

Greetings,

A new daily build of CHIRP is available.  This includes changes made
directly to the tree yesterday, and may include additional features,
bug fixes, and/or bugs.  If you are interested in trying it, grab it
from the following location:

  http://trac.chirp.danplanet.com/chirp_daily/daily-20210416


A list of the changes included in this build (since the last daily)
follows:

Changes for Build #647
[Jim Unroe <rock.unroe at gmail.com>] [BJ-318] Add support for the Baojie BJ-318

This patch adds support for the Bajoie BJ-318 mobile radio.

Research and main coding by Mark Hartong
Assistance, pep8 compliance and submission by Jim Unroe

related to #6235

[Jim Unroe <rock.unroe at gmail.com>] [BJ-318] Driver prep to make ready to support the Baojie BJ-318

This patch makes changes to the lt725uv.py driver to facilitate the addition
of support for the Baojie BJ-318.

The features and settings of the radio models that this driver currently
supports are not affected.


related to #6235

[Jim Unroe <rock.unroe at gmail.com>] [LT-725UV] Fix for incorrect range specified for VFO B Initial Chan: setting

The Settings -> VFO B-Lower Settings -> Initial Chan:" setting currently
provies a selection range of 0-127. This range should be 1-128.

This patch updates the Initial Chan: seting to provide the correct range.

Models affected:
LUITON LT-725UV
Baojie BJ-218 / Hesenate BJ-218 / Zastone BJ-218

Fixes #8979

[Dan Smith <dsmith at danplanet.com>] Fix base match_model definition for zero memsize

The base match_model() implementation defaults to comparing the file
size to Radio._memsize in order to identify the proper driver for a
given file (for legacy files only). Since the default for the _memsize
in CloneModeRadio is zero, any empty file will be identified as a
match by any new driver that relies on metadata and does not (nor does
it need to) override _memsize. The first driver returned from the
directory dict that "matches" will be returned.

This fixes #8967 which manifests as a failure to run File->New. Since
the new file is zero length, we fail to properly load the CSVRadio
driver that we need because we incorrectly allow the directory to
match the zero length against everything.