add German signal Bü5 (ring) with and without two stripes
add German Bü5 signal (ring) to style
Merge pull request #73 from Nakaner/ring-sign

Added german ring sign Bü 5 to signalling layer
Added german ring sign Bü 5 to signalling layer legend
Added german ring sign Bü 5 to signalling layer legend
make arrows of German Hp semaphore signals thicker
Merge pull request #74 from Nakaner/hv-semaphore-better

Make arrows of German Hp semaphore signals thicker