v1.9.7 Flat GUI appereance

**Fixed exception error after mono upgrade (c6.8+) and bumped .NET Framework to 4.8, new version of Newtonsoft dll

**Fixed screen not fitting for resolution 1200x800.

**Made GUI more flat, so it looks more or less the same on Windows and Linux with mono.

**Otherwise identical to 1.9.5.7.

**Video demonstration:

vct2.mp4

**LINUX NOTE: Since new version needs ffplay and it can't be found as a static build for Linux you have to both install ffmpeg package and copy the binaries that I included, ffmpeg and ffprobe manually to /usr/bin/.

LINUX INSTALLATION: I added small scripts to automate installations.
For Debian, Ubuntu, etc. with APT package manager download install_vct_apt.sh, and run it (provide sudo credentials):
./install_vct_apt.sh
or just double click it - execute in terminal! It will update packages, download VCT_mono_binary and create desktop file vct.desktop which you can double click to run the program.
Always start VCT.exe with option "Run mono in terminal".

For Fedora, Centos, etc. with YUM package manager download install_vct_apt.sh, and run it (provide sudo credentials):
./install_vct_apt.sh
or just double click it - execute in terminal! It will update packages, download VCT_mono_binary and create desktop file vct.desktop which you can double click to run the program.

Program will be installed in $HOME/VCT_mono/.

For other distros that use other package managers, please read INSTALL_README.txt and install manually.
Manual installation is just exctraction to specific directory (e.g. home) and copying ffmpeg binaries, which is described in README.