Add script that updates LOOT's version number

Closes #666.

package.json

@@ -14,6 +14,7 @@
   "private": true,
   "dependencies": {
     "fs-extra": "^0.30.0",
+    "replace": "^0.3.0",
     "vulcanize": "^1.14.5"
   },
   "devDependencies": {

scripts/set_version_number.js

@@ -0,0 +1,89 @@
+#! /usr/bin/env node
+'use strict';
+
+const path = require('path');
+const replace = require('replace');
+
+function updatePreCommitHookScript(version) {
+  replace({
+    regex: /--package-version=[\d.]+/,
+    replacement: `--package-version=${version}`,
+    paths: [path.join('scripts', 'git', 'pre-commit')],
+    silent: true,
+  });
+}
+
+function updateInstallerScript(version) {
+  replace({
+    regex: /#define MyAppVersion "[\d.]+"/,
+    replacement: `#define MyAppVersion "${version}"`,
+    paths: [path.join('scripts', 'installer.iss')],
+    silent: true,
+  });
+}
+
+function updateCppFile(version) {
+  const file = path.join('src', 'backend', 'app', 'loot_version.cpp.in');
+  const versionParts = version.split('.');
+
+  replace({
+    regex: /LootVersion::major = \d+;/,
+    replacement: `LootVersion::major = ${versionParts[0]};`,
+    paths: [file],
+    silent: true,
+  });
+
+  replace({
+    regex: /LootVersion::minor = \d+;/,
+    replacement: `LootVersion::minor = ${versionParts[1]};`,
+    paths: [file],
+    silent: true,
+  });
+
+  replace({
+    regex: /LootVersion::patch = \d+;/,
+    replacement: `LootVersion::patch = ${versionParts[2]};`,
+    paths: [file],
+    silent: true,
+  });
+}
+
+function updateResourceFile(version) {
+  const file = path.join('src', 'resource.rc');
+  const commaSeparatedVersion = version.replace(/\./g, ', ');
+
+  replace({
+    regex: /VERSION \d+, \d+, \d+/g,
+    replacement: `VERSION ${commaSeparatedVersion}`,
+    paths: [file],
+    silent: true,
+  });
+
+  replace({
+    regex: /Version", "\d+\.\d+\.\d+"/g,
+    replacement: `Version", "${version}"`,
+    paths: [file],
+    silent: true,
+  });
+}
+
+function main() {
+  if (process.argv.length !== 3) {
+    console.error('Invalid number of arguments given. Only one argument (the new version number) is expected.');
+    process.exit(1);
+  }
+
+  const newVersion = process.argv[2];
+
+  if (newVersion.split('.').length !== 3) {
+    console.error('The version number must be a three-part semantic version.');
+    process.exit(1);
+  }
+
+  updatePreCommitHookScript(newVersion);
+  updateInstallerScript(newVersion);
+  updateCppFile(newVersion);
+  updateResourceFile(newVersion);
+}
+
+main();