Texture cleanup (#151)

Big cleanup of all textures in the modpack.
- Moved alternate textures to `.textures/alternate`
- Moved unused textures to `.textures/unused`
- Removed duplicate textures
- Optimized some textures
- Fixed misplaced textures
- Fixed incorrect name of a texture
- Adjusted export-ignores to exclude unused textures

.gitattributes

@@ -1,29 +1,7 @@
 # Auto detect text files and perform LF normalization
 * text=auto
 
-# Custom for Visual Studio
-*.cs     diff=csharp
-*.sln    merge=union
-*.csproj merge=union
-*.vbproj merge=union
-*.fsproj merge=union
-*.dbproj merge=union
-
-# Standard to msysgit
-*.doc	 diff=astextplain
-*.DOC	 diff=astextplain
-*.docx diff=astextplain
-*.DOCX diff=astextplain
-*.dot  diff=astextplain
-*.DOT  diff=astextplain
-*.pdf  diff=astextplain
-*.PDF	 diff=astextplain
-*.rtf	 diff=astextplain
-*.RTF	 diff=astextplain
-
 # Release export attributes
-technic/spec/** export-ignore
-.github/** export-ignore
-.luacheckrc export-ignore
-.mailmap export-ignore
 integration-test.sh export-ignore
+**/spec export-ignore
+**/.* export-ignore