Initial commit, work in progress
New submenu in "Advanced" menu, do get the status of the log area:
displays percentage full, as well as time remaining at current log
interval. Also tells if logging is disabled.

Besides this new feature, a lot of comments added in various places to
help me understand the firmware...
Also monitor logging paused, while we're at it. Useful in case the unit
is connected to a (buggy) backend and somehow got stuck in paused mode
from the serial link.

Also bumped release number.
And display number of records used out of the max number of log records,
at the bottom of the screen.
Merge pull request #57 from elafargue/logmonitor

Log status menu