Main

Adding new script to build ffmpeg and dependencies. Apparently I spent a
good while working on this locally but never committed it.

Adding update from github: https://github.com/packjpg/packJPG/commit/93a7dfbe1fb9aa2aee763cc5b8a16c14b2f66c8c

Minor updates mainly to pwmgr to fix Gtk3.0 deprecations.

Update generate rows script for repayment schedule.

Adding automated watering system scripts.

Update display.py with latest root fs device path.

Thanks to hbkcd, the interface portion can now just be some javascript
(and CSS and HTML).

Add link time optimization to compiler (linker) flags.

Add link time optimization to compiler (linker) flags. Also change
default install path to /opt/local.

Fixing items suggested by clang-tidy.