[Cin] Today's GIT checkin includes fixes + Ctrl-s for save session

[Igor BEGHETTO]

All my personal opinion.

I am not an old Cinelerra-GG user like most of You (I am using 
Cinelerra-GG since January 2018 ) and, for me, some shortcuts should be 
changed (I already speak about).

For me there are foundamental shortcuts that a NLE must have, for 
example J-K-L for PlayBackward-Stop-PlayForward and I-O for In point-Out 
point.
Ctrl+S is good for me and Ctrl+Z shortcut would be welcome. And, I 
think, the old "Save 's' " could be deleted. I understand the old users 
but, the old users can do an effort to change (hey!, I no longer have 
the shortcuts for the old "Move tracks Up/Down"). I think that Ctrl+S 
for Save is a standard.

IMHO some shortcuts could go away and to be available for feature, new 
or old, more used.
For me a shortcut should be assigned to a tool most frequently (or 
important?) used.
For example I would not assign any shortcuts to the following items in 
File menu:
- BD Render... (Ctrl+Shift+D)
- DVD Render... (Alt+D)
- SubTitle... (Alt-Y)

About Speed feature:
Very good. Thanks!
I noticed that Speed tool must be used with care because the different 
types of keyframes can upset your work.
IMHO, I would have preffered to be implemented at the clip level that 
you can change with RMB menu on it, and the Speed lines on the track to 
be hidden. Of course, this way, could not have the Speed Ramp.

About F_minterpolate:
I have done a short test. On my Charlie F_minterpolate can not work in 
real time (Proxy without Scaler enabled). I have to use a workaroud. So 
I can decide if create a SlowMo with FFmpeg by command line or inside 
Cinelerra-GG: good!

IgorBeg