add support for German main signals type Hl
add German Hl distant signals, fixing bugs in Hl signal code
add German Hl combined signals
Merge remote-tracking branch 'upstream/master' into hl-signal-integration
Merge branch 'master' into hl-signal-integration

Conflicts:
	styles/signals.mapcss
Merge pull request #82 from Nakaner/hl-signal-integration

Hl signal integration