Fix typos.

src/api/dotnet/Context.cs

@@ -475,7 +475,7 @@ namespace Microsoft.Z3
         /// Update a datatype field at expression t with value v.
         /// The function performs a record update at t. The field
         /// that is passed in as argument is updated with value v,
-        /// the remainig fields of t are unchanged.
+        /// the remaining fields of t are unchanged.
             /// </summary>
         public Expr MkUpdateField(FuncDecl field, Expr t, Expr v)
         {

src/api/dotnet/Optimize.cs

@@ -25,7 +25,7 @@ using System.Linq;
 namespace Microsoft.Z3
 {
     /// <summary>
-    /// Object for managing optimizization context
+    /// Object for managing optimization context
     /// </summary>
     public class Optimize : Z3Object
     {

src/api/dotnet/dotnet35/Readme.NET35

@@ -4,7 +4,7 @@ instructions are as follows:
 
 In the project properties of Microsoft.Z3.csproj:
 - Under 'Application': Change Target framework to .NET Framework 3.5
-- Under 'Build': Add FRAMEWORK_LT_4 to the condidional compilation symbols
+- Under 'Build': Add FRAMEWORK_LT_4 to the conditional compilation symbols
 - Remove the reference to System.Numerics
 - Install the NuGet Package "Microsoft Code Contracts for Net3.5":
   In the Package Manager Console enter Install-Package Code.Contract