Change the tool flow to prevent bad uploads

[jotego]

jtupdate adds file to JTBIN by default, which has caused inadverted uploads of broken cores a few times. The issue arises as:

1. while working on a release for system x (say mist)
2. I check that other system (say mister) is still healthy by running a batch compilation using jtupdate
3. when I commit the changes to jtbin, the mister files get uploaded too, despite there was no intention to do so

Some solutions:

• The beta check lists includes this item but it is not checked for non beta updates
• Remember to use jtupdate with the --nogit flag?
• jtupdate to work on a branch to force a manual merge?

[jotego]

Keeping JTBIN clean with git clean -f before working on a new update seems to prevent this problem. jtupdate should check that JTBIN is clean before running

[jotego]

Changes made in JTUTIL v1.0.0 and JTFRAME v1.4.3