Fix Nitra.Compiler.nuspec & update NuGet.exe

Author: VladD2

ExternalTools/NuGet.exe

@@ -4,12 +4,12 @@
     <id>Nitra.Compiler</id>
     <version>$NitraBuildVersion$</version>
     <title>Nitra compiler macro library</title>
-    <authors>JetBrains</authors>
+    <authors>Nitra team</authors>
     <description>Nitra compiler macro library for Nemerle compiler.</description>
     <projectUrl>https://confluence.jetbrains.com/display/Nitra</projectUrl>
     <licenseUrl>http://opensource.org/licenses/BSD-3-Clause</licenseUrl>
     <requireLicenseAcceptance>false</requireLicenseAcceptance>
-    <copyright>JetBrains Inc.</copyright>
+    <copyright>Nitra team</copyright>
   </metadata>
   <files>
     <file src="$OutputPath$Nitra.Runtime.???" target="tools" />
@@ -18,4 +18,4 @@
 	<file src="Nitra.Compiler.props" target="build\net" />
 	<file src="$OutputPath$Nitra.Runtime.???" target="lib\net" />
   </files>
-</package>
+</package>