Add ability to configure working directory for unzipping/running node modules

Added support for environment variable WEBCOMPILER_WORKING_DIRECTORY in
CompilerService.  If set, we will unzip node.exe and node modules into
a subdirectory of this directory instead of into the system temp directory.

This is intended for CI or build server environments where temp directories
are often cleaned after every run, or are set per-build-agent.

Author: nathan-ainslie-vectorsolutions

.gitignore

@@ -25,4 +25,5 @@ x64/
 _NCrunch_WebCompiler#Node
 
 #Node
-src/WebCompiler/Node/node_modules/*
+src/WebCompiler/Node/node_modules/*
+src/WebCompiler/Node/node.exe

src/WebCompiler/Compile/CompilerService.cs

@@ -10,13 +10,20 @@ namespace WebCompiler
     /// </summary>
     public static class CompilerService
     {
-        internal const string Version = "1.4.167";
-        private static readonly string _path = Path.Combine(Path.GetTempPath(), "WebCompiler" + Version);
+        internal const string Version = "1.12.0";
+        internal const string WorkingDirectoryEnvVarName = "WEBCOMPILER_WORKING_DIRECTORY";
+        private static readonly string _path = GetWorkingDirectoryPath();
         private static object _syncRoot = new object(); // Used to lock on the initialize step
 
         /// <summary>A list of allowed file extensions.</summary>
         public static readonly string[] AllowedExtensions = new[] { ".LESS", ".SCSS", ".SASS", ".STYL", ".COFFEE", ".ICED", ".JS", ".JSX", ".ES6", ".HBS", ".HANDLEBARS" };
 
+        internal static string GetWorkingDirectoryPath()
+        {
+            var envValue = Environment.GetEnvironmentVariable(WorkingDirectoryEnvVarName);
+            return Path.Combine(envValue ?? Path.GetTempPath(), "WebCompiler" + Version);
+        }
+
         /// <summary>
         /// Test if a file type is supported by the compilers.
         /// </summary>