Add gyb code generator

Author: stackotter

Diff for: .gitignore

@@ -6,3 +6,4 @@ xcuserdata/
 DerivedData/
 .swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata
 /.vscode
+*.pyc

Diff for: generate.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+# This script compiles all .gyb files in the Sources directory
+
+find Sources -name '*.gyb' | \
+    while read file; do \
+        ./gyb/gyb --line-directive '' -o "${file%.gyb}" "$file"; \
+    done

Diff for: gyb/gyb

@@ -0,0 +1,3 @@
+#!/usr/bin/env python2.7
+import gyb
+gyb.main()