Switch the output to a stdio text stream.

Also, flush it.
Update version info the 1.0.12
Update the CLI strings.
SystemDialog now has a button subcommand.
Don't store the scene. Check the scene, check app as fallback.

Previously, some commands would store the scene - this isn't needed.
Some commands also only checked the current scene for objects which means
we'll lose some that are off-screen (dialogs are a good example) which
may not be what we want.
Update release notes
cppcheck/vera++ fixes