add nether armor and nether shield (#65)

* add texture files for nether based 3d_armor
* add texture files for nether based shield
* perpare for nether armor
* add nether armor
* add translation for nether armor
* add translation for nether armor
* add nether shield
* add nether shield translation
* add nether armor texture preview info
* add nether shield texture preview info
* add nether to settingtypes.txt
* add german translation for armor
* add german translation for shields
* Nether armor stats modified.
* Modify Nether Shield Stats

* Update inline documentation

3d_armor/textures/preview_index.txt

@@ -38,6 +38,11 @@
 3d_armor/textures/3d_armor_leggings_crystal.png:legs
 3d_armor/textures/3d_armor_boots_crystal.png:feet
 
+3d_armor/textures/3d_armor_helmet_nether.png:head
+3d_armor/textures/3d_armor_chestplate_nether.png:torso
+3d_armor/textures/3d_armor_leggings_nether.png:legs
+3d_armor/textures/3d_armor_boots_nether.png:feet
+
 3d_armor/textures/3d_armor_helmet_admin.png:head
 3d_armor/textures/3d_armor_chestplate_admin.png:torso
 3d_armor/textures/3d_armor_leggings_admin.png:legs