Modernizing libavoid

[erwinliong]

Is it possible to have the following:

• Convert solution *.sln or project *.vcxproj to a later version of Visual Studio (such as VS2015)
• Correct static analysis warnings
• Correct the use of banned functions as per https://msdn.microsoft.com/en-us/library/bb288454.aspx
• Correct the coding error of "==" instead of "=" at .\libavoid\orthogonal.cpp @ Line 2179 "if ((displayRoute.size() == 2) && (endsInShapes = 0x11))"
• Use of nullptr as per https://msdn.microsoft.com/en-us/library/4ex65770.aspx

Thank you.