Enhance .gitattributes content

 - Fix the standard CRLF/LF line ending issue for contributors
 - Non destructive settings for solution and projects files
 - Auto detection of binary files
Fix missing trailing newlines
Remove useless using directives
Add build tooling

 - Cross platform .msbuild file
 - Windows launcher
 - Mono launcher

Those files have been adapted from the LibGit2Sharp project
Add Travis build script