Some Minor Bug Fixes and improvements

1. Selecting [all] fields in graph config will cyclically assign alternate colors to fields (starting with the selected color)
2. When entering filters on configuration file, the updating list would generate errors if the grep statement was invalid. (could only be seen in developer mode).
3. Video export now fixed (still no sound though :-( ); also if you hide an item on the graph display (hide the craft for example), then it will also be hidden on exported video.
4. Cleanup hide/display of popup table (key 'T'); originally if the table was hidden and you popped up the overlay, when you hid the table again, it would show at the bottom of the page; now it will return to its originally selected state.
5. You can load 2 configuration dump files; if you load a second one with the the word 'default' in its filename (e.g. Betaflight V2.7.2 Default.txt) then this file will be used as a baseline for the first loaded file; all differences between the two files will be highlighted in red. Also, once a "default" file is loaded, it will be cached and autoloaded next time you open up the log viewer; thus you only have to re-load the "default" file if and when the default values are changed.
6. Header and Scaling now Betaflight v2.8.0 compliant; will auto-detect version from log file and scale accordingly.
7. Analyser Crash fix for crash that occurs if switching between many logs repeatedly (more than 6 times per session).
8. Code improvements for operation in Linux.
9. Additional User Settings Dialog for custom motor mixes (for those not running a standard X quad). Note that this setting only affects the craft overlay icon that is displayed. Deselecting "Custom" will display craft the traditional way (this is the default, you only need to change it if you are running a special motor configuration).
10. When using the Marker function (M), the time offset from the marker also shows the frequency in Hz (so if you mark the peak of a wave, then scroll to the next peak, you can quickly see the frequency of the wave). Quickly identify the frequency of your noisy gyro's.