Since the update to the newer red5, seeking in flv files (webcams in
particular are noticable) has been broken, resulting in cameras
appearing to "hang" any time there is a cut in the generated video -
which happens when start/stop button is pushed, or when cameras are
added or removed.

We can detect the problematic video files because the timestamp of the
first frame is large (old red5 versions always set first frame
timestamp to 0.001 seconds). If we see a file like this, having ffmpeg
remux the file - rewriting the timestamps and index - works around the
problem.

RaP: Merge the sanity script from master branch

 - shorten timer to wait in case other red5 conn disconnect. Need to …

 - put back accidentally deleted log to show why screenshare failed t…

 - allow to configure using config.xml that region is default choice …

Due to improvements in the recording scripts, most of the stuff the sanity
script was checking for is no longer needed (missing/corrupt video files
are handled by the processing scripts). The version of this script in
master has been cleaned up so that the only things it does are:

- Check that the events.xml exists and is properly formatted xml
- Rebuild flv files from red5 .flv.ser/.flv.info files

The script from master is compatible with the 2.0 code, so just use it
as-is.

This fixes a problem where following the recent red5 upgrade in 2.0 branch,
an flv file is never written for webcam streams where no frames were
received, despite there being recording events.

 - make reconnect wait timer configurable. This timer waits for a period of time in case other connections
   disconnects before initiating reconnection. Default is 2 seconds.

 - shorten timer to wait in case other red5 conn disconnect. Need to initiate reconnect as soon as possible.

Tested, works well

Add a 64-bit check to the Firefox 60+ upload block

Temporarily disable uploading on Win Firefox 60+

 - add some kind of check to uploaded file

   NOTE: This doesn't fix issue with uploading file with FF 60 on Windows 10.

 - webrtc screenshare should not create another connection to red5 sc…

Redesign of screenshare select with win10 chrome warning

RaP: Scale to a square when generating slide images for pres. format

This improves the quality of portrait documents, before they were
1200px when landscape documents got 1600px.

Switching to scaling to a square means that we can use the "-scale-to"
option on pdftocaio, which means that it generates images directly
at the desired size. This can save quite a bit of time (and memory)
if a document was uploaded with extremely large page size.

RaP: Improve check for record events in archive, sanity scripts

There's some cases where you can get 0-duration recordings due to
recording event placement (e.g. a single recording event is the last
event in the events.xml). Detect these cases, and treat them like
no recording marks in the archive script (it will stop the recording
from being automatically processed).

I've also adjusted the sanity script to detect these cases and error
out. The recording processing scripts cannot handle 0-length recordings,
you have to manually edit the events. I've added a message to the
sanity log about this.

Support metadata with improper format

Change abs paths to use baseName config 

[HTML5 Client] Server-side timestamps in chat messages.

 - change log timestamp format so they are all the same

Rename function to be consistent with state name.