split up JOSM presets

There is now one track and station preset and one signal preset. This makes
it easier to develop and use presets for different countries or working
rules (remember the differences between trams and trains!).
add abbrevations of Bü signals, Pf 1/2 and Ne 1, Ne 2, So 106

Some users (e.g. myself) prefer to type the signal abbrevation after pressing
F3 in JOSM.
Merge remote-tracking branch 'upstream/master' into josm-template-split
add abbrevations for some signals
add abbrevations for German signals
German light minor signal Sh0 has been renamed to Hp0
add new tag for resetting switches (railway:switch:resetting=yes/no)
add value "unknown" for unknown display values
add abbrevation for German Ne 5 signal
add agreements from Cologne Meeting

- railway:signal:snowplow:order -> railway:signal:snowplow:type
- add Schachbretttafel (checker board)
rename infrastructure tagging scheme, add German name
changed name to "OpenRailwayMap Infrastructure DE"

Even the infrastructure presets should be country-specific because
some countries have different types of derailers, train protection
systems etc.
Merge branch 'master' into josm-template-split

Conflicts:
	josm-presets/de.xml
change "unknown" to "?" as documented in the protocols of the meetings
Merge pull request #83 from Nakaner/josm-template-split

Split JOSM template into signals and infrastructure, applied some tagging changes