Fix painting of landing altitude (aka AGL warning).
SIProperty for SI:: types.
Migrate FMS to use SIProperties.
Remove unused file.
Fix here, fix there.
Migrate EFIS instrument to use SIProperties.
Migrate the rest of instruments to SIProperties.

Add UnitParser to parse strings like "50 kt".
Strong-typed property database.
Correctly paint minimum value on speed ladder - without previous digit.
Use strong typed properties database.
Remove Roboto fonts, replace them with monospaced Crystal.

Fix some details in rendering. Add shadow below aircraft "triangle"
on HSI, under wind arrow, etc.
Fix FMS bug when calculating vertical track.

Used asin(), should be atan().