Some fixes in response to user observations.

1. Bump version to v2.5.8
2. Fix to Analyser display going blank for users using logging to onboard flash memory.
3. Always start with the values table hidden; pressing key 'T' will toggle the table; pressing the toolbar button will put it back at the bottom of the graph.
4. Fix Issue #36; viewer was not parsing version number correctly for filter scaling. Refactored functions to use library semver.
5. UI Overhall; better support for smaller screens, toolbar will collapse into menu's when there's not enough room.
6. BF3.1 Compatibility, corrected filter values showing zero and removed PID controller type from header display.
7. Add Dshot to protocol definitions on header dialog.
8. Update for gyro scaling in BF3.1.0; scaling is now handled by flight controller

Notes

1. The analyser display can go blank when using log files uploaded from flash memory. The problem occurs if you change log from the drop-down menu before displaying the analyser. Then when you do display the analyser, and zoom in, the analyser goes blank. This version should cure this.