Player - Max open files

When having an eCAL measurement with many topics on Ubuntu, you may experience crashes. This is caused by a Linux security feature that limits the number of open file descriptors (to 1024 by default). As each topic relies on multiple files (used by the shared memory transport layer), that limit may be triggered and cause a crash.

Please follow the following steps to increase the allowed number of open files.

Add to /etc/sysctl.conf:
```
  fs.file-max = 65535
```
Apply this setting:
Terminal window
```
  sudo sysctl -p
```

Add to /etc/security/limits.conf: Replace YOUR_USERNAME with your actual username!

  YOUR_USERNAME     soft     nproc          65535
  YOUR_USERNAME     hard     nproc          65535
  YOUR_USERNAME     soft     nofile         65535
  YOUR_USERNAME     hard     nofile         65535

Add to both /etc/systemd/user.conf and /etc/systemd/system.conf:
```
  DefaultLimitNOFILE=65535
```
Reboot

Now the player should play the measurement just fine.