Simplify logic in getModulesVersion() function

Use value of release.semver to determinate file name and location with NODE_MODULE_VERSION define,
and to read this file depending on target Node.js version.

Tested with Node.js versions: 0.8.4, 0.10.25, 0.11.4, 0.11.5, 0.12.0, iojs-1.0.0, iojs-2.0.0, iojs-3.0.0, 4.X, 5.X

Added verbose log messages for the target_arch, target_platform, and target_modules_version variables.

lib/configure.js

@@ -82,25 +82,35 @@ function configure (gyp, argv, callback) {
 
   function getModulesVersion(nodeDir) {
 
-    var sources = [
-      path.join(nodeDir, 'include/node/node_version.h'),
-      path.join(nodeDir, 'src/node_version.h'),
-    ]
+    var name, source, version
+
+    // NODE_MODULE_VERSION is defined in different files
+    // depending on the target Node.js version
+    if (semver.gte(release.semver, '3.0.0')) {
+      name = 'include/node/node_version.h'
+    } else if (semver.gt(release.semver, '0.11.4')) {
+      name = 'src/node_version.h'
+    } else {
+      name = 'src/node.h'
+    }
+    name = path.join(nodeDir, name)
 
-    for (var i = 0; i < sources.length; ++i) {
-      try {
-        var source = fs.readFileSync(sources[i], { encoding: 'utf8'})
-        var version = source.match(/^#define\s+NODE_MODULE_VERSION\s+(\d+)/m)
-        if (!version) {
-          err = new Error("can't find #define NODE_MODULE_VERSION in " + sources[i]);
-          callback(err);
-        }
-        return parseInt(version[1], 10);
-      }
-      catch (e) {}
+    try {
+      source = fs.readFileSync(name, { encoding: 'utf8'}) 
+    } catch (e) {
+      err = e
+      callback(err)
+      return undefined
+    }
+
+    version = source.match(/#define\s+NODE_MODULE_VERSION\s+\(?(\S+)\)?/)
+    if (version === null) {
+      err = new Error('#define NODE_MODULE_VERSION not found in ' + name)
+      callback(err)
+      return undefined
     }
-    err = new Error("can't read node_version.h in " + nodeDir)
-    callback(err);
+    version = parseInt(version[1])
+    return version
   }
 
   function createBuildDir () {
@@ -149,12 +159,15 @@ function configure (gyp, argv, callback) {
 
     // set the target_arch variable
     variables.target_arch = gyp.opts.arch || process.arch || 'ia32'
+    log.verbose('build/' + configFilename, 'target arch: ' + variables.target_arch)
 
     // set the target_platform variable
     variables.target_platform = process.platform
+    log.verbose('build/' + configFilename, 'target platform: ' + variables.target_platform)
 
     // set the target modules version
     variables.target_modules_version = getModulesVersion(nodeDir)
+    log.verbose('build/' + configFilename, 'modules version: ' + variables.target_modules_version)
 
     // set the node development directory
     variables.nodedir = nodeDir