add support for difference between German Vr reapeters and Vr signals

If a German light Vr signal is tagged to be not a repeater or if the
tag railway:signal:distant:repeated is not set, it is rendered as normal
signal. If the tag is set yes, it will be rendered as repeater.
differentiate between the fuctions of German Hp and Vr light signals
improve comments in code
increase icon size
rename SVGs of German Hp and Vr light signals
remove old code
improve rendering of German semaphore main signals

German semaphore main signals look different in rendering if they
have different functions. The code is almost the same as for German
H/V light signals.
improve rendering of German distant semaphore signals
Merge pull request #55 from Nakaner/signal-style-DE-distant-signals

add support for difference between German Vr reapeters and Vr signals