Autosave HEX file in sketch folder

[Sembazuru]

Now that issue #6 (Allow any Hex file upload) is closed, I would propose to have the generated HEX file optionally copied from the build location to the sketch folder. But, only in these instances:

• If there is no HEX file in the sketch folder (but not if there is no sketch saved in the sketch folder or if the sketch folder doesn't exists to catch compiles before the first save).
• If there is an autosave before compiling (see issue #3 (Option to autosave when compiling)).
• If the existing saved sketch file is newer than the existing saved HEX file. (This might make the second bullet point redundant depending on when the filedates are checked relative to when any potential autosave may happen.)

This allows for easy archive of the HEX file so one doesn't have to re-compile every time they want to upload an existing sketch. The check should probably be done against the default HEX filename instead of all HEX files to allow the user to keep a back-catalog of HEX files.

Especially useful far(?) in the future when one has an old sketch (from now) that doesn't compile with the latest IDE in the future. One wouldn't have had to remember now to pull the HEX file from the build path to have something that can be uploaded in the future without having to re-tool the sketch for the future IDE. (Sorry if the future and past stuff is hard to grasp, it should make sense if you think like a Time Lord.) ;-P See how IDEv1.x broke all (most?) previous sketches and libraries from before as a precedent to why this would be (and would have been) valuable.

[eried]

There is any special reason you want to avoid compilation? I mean do you really remember what the hex file like to just use the hex file?

I can think on making /hex folder in the sketch folder with name_datetime.hex on every upload (as you say with the auto-save) but I am not just sure if this will be useful... because I personally backup less than couple of hex files I can remember, so the current "show compilation folder" button fulfills my needs (I am trying to find a valid reason to include this, that might be an annoyance for some people)