Fix AssImp compilation with VS 2017. Remove cmake_vs2013.bat. Closes #2191.

Source/ThirdParty/Assimp/code/X3DImporter.cpp

@@ -95,8 +95,8 @@ struct WordIterator: public std::iterator<std::input_iterator_tag, const char*>
         end_ = other.end_;
         return *this;
     }
-    bool operator==(WordIterator &other) const { return start_ == other.start_; }
-    bool operator!=(WordIterator &other) const { return start_ != other.start_; }
+    bool operator==(const WordIterator &other) const { return start_ == other.start_; }
+    bool operator!=(const WordIterator &other) const { return start_ != other.start_; }
     WordIterator &operator++() {
         start_ += strcspn(start_, whitespace);
         start_ += strspn(start_, whitespace);

cmake_vs2013.bat

@@ -1,23 +0,0 @@
-::
-:: Copyright (c) 2008-2017 the Urho3D project.
-::
-:: Permission is hereby granted, free of charge, to any person obtaining a copy
-:: of this software and associated documentation files (the "Software"), to deal
-:: in the Software without restriction, including without limitation the rights
-:: to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-:: copies of the Software, and to permit persons to whom the Software is
-:: furnished to do so, subject to the following conditions:
-::
-:: The above copyright notice and this permission notice shall be included in
-:: all copies or substantial portions of the Software.
-::
-:: THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-:: IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-:: FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-:: AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-:: LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-:: OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-:: THE SOFTWARE.
-::
-
-@"%~dp0cmake_generic.bat" %* -VS=12