added Czech hedgehog by @JOoGraphics

http://content.open-ra.org/?p=detail&table=units&id=339
Added Utility Poles by @CombineCR

http://content.open-ra.org/?p=detail&table=units&id=330
Added ammo boxes by @CombineCR

http://content.open-ra.org/?p=detail&table=units&id=324
Added a new mine that seeds gems by @CombineCR

http://content.open-ra.org/?p=detail&table=units&id=323
added a tank trap by @CombineCR

http://content.open-ra.org/?p=detail&table=units&id=322
added a temperat rice field by @JOoGraphics

http://content.open-ra.org/?p=detail&table=units&id=307
Added Russian city building by @JOoGraphics

http://content.open-ra.org/?p=detail&table=units&id=308
added an Asian hut by @JOoGraphics

http://content.open-ra.org/?p=detail&table=units&id=351

Conflicts:
	mods/ra/rules/civilian.yaml
consistently name tank traps
more descriptive and consistent name for utility poles
split ammobox into 3 single SHPs because of editor limitations
Merge pull request #3512 from Mailaender/community-assets

Added decorative pixelart contributed by the community