Changes for upcomming 1.8.0

Changes for upcomming 1.8.0:

1.8.0 (RC3) contains:

- to make the command functions working, all code from the
button-handlers had to be moved into single functions
- Sorted much of the functions by purpose, removed old comments
- removed code from the timer callback that was supposed to calc the
next time interval it has to be called for time compression (Flight Time
now is calculated by X-Plane)
- removed "Tacho Code" as it's no longer supported by FSE
- updated logfiles texts to look more common

- Script is now "Time Compression Safe" - changed code to use X-Plane's
buildin "Flight Time", so time compression levels like 1.5 are possible
without loosing FSE flight time
- Resend button (can send the last URL again (enabled after arrived(),
disabled on StartFlight())

- new DataRef exported: "fse/status/flighttime"
- Added X-Plane CMD: "fse/flight/start",  "fse/flight/cancelArm",
"fse/flight/cancelConfirm"
- Added X-Plane CMD: "fse/window/show",  "fse/window/hide",
"fse/window/toggle"

- changed links to download updates from github to test if update
function still works