Notes on how to use git2changelog.sh

Since I always forget the format of the parameters passed to git log
Flow up error states from routing so the GUI can display the failing result.
Refactor time from start track property label update
Fix crashing on double clicks - properly initialize variable.

Fixes previous commit on this file to support GLIB 2.24
(SHA1:5a8048bb6a980b0b969cb8864bdcce16607f9581)
Report download failures in the statusbar.

Tile and DEM download failures are now shown in the GUI,
 rather than just messages on the console.

Use enumerated failure states.
Allow clearing and copying of the information message in the statusbar.
Optimize tooltip message generation, remove unnecessary track iterations.

Limit vik_track_get_tp_last() usage, since it uses g_list_last(),
 which in turn iterates through the list to find the last trackpoint.

Thus cache the last trackpoint before multiple usage in tooltip generation.

Hopefully this will make it more likely these tooltips will get shown in Windows.