Add Python 3 support on Windows (#121)...

Tested using Python 3.4 / 3.5 / 3.6. Only 32-bit. Everything works good.

Update tools for Python 3.

On Windows build.py tool will call build_cpp_projects.py to build C++
projects. On Linux and Mac C++ projects are built using Makefiles.

There are still deprecated .vcproj files across directories, however
they are all deprecated and not used anymore.

automate.py --prebuilt-cef works on Python 3. However --build-cef
depends on upstream automate-git.py which supports only Python 2.

Minor fixes to build instructions.

docs/Build-instructions.md

@@ -55,7 +55,7 @@ and libraries from GitHub Releases:
 2) Download [ninja](https://github.com/ninja-build/ninja) 1.7.2 or later
    and add it to PATH.
 
-3) Download [cmake](https://cmake.org/download/) 3.7.2 or later and add
+3) Download [cmake](https://cmake.org/download/) and add
    it to PATH.
 
 4) For Python 2.7 Install "Visual C++ Compiler for Python 2.7"
@@ -147,6 +147,9 @@ requirements common for all platforms.
 
 ### Windows
 
+* Download [ninja](https://github.com/ninja-build/ninja) 1.7.2 or later
+  and add it to PATH.
+* Download [cmake](https://cmake.org/download/) and add it to PATH.
 * Install an appropriate MS compiler for a specific Python version:
   https://wiki.python.org/moin/WindowsCompilers
     * For Python 2.7 install "Microsoft Visual C++ Compiler for Python 2.7"
@@ -208,6 +211,10 @@ requirements common for all platforms.
 
 * MacOS 10.9+, Xcode5+ and Xcode command line tools. Only 64-bit builds
   are supported.
+* Download [ninja](https://github.com/ninja-build/ninja) 1.7.2 or later
+  and add it to PATH.
+* Download [cmake](https://cmake.org/download/) and add it to PATH.
+
 
 
 ### All platforms

src/compile_time_constants.pxi

@@ -1,3 +1,3 @@
 # This file was generated by setup.py
 DEF UNAME_SYSNAME = "Windows"
-DEF PY_MAJOR_VERSION = 3
+DEF PY_MAJOR_VERSION = 2

tools/apidocs.py

@@ -36,7 +36,7 @@ def api_index():
         if "API-" in file_:
             continue
         with open(file_, "rb") as fo:
-            raw_mdcontents = fo.read()
+            raw_mdcontents = fo.read().decode("utf-8")
 
         parsable_mdcontents = re.sub(r"```[\s\S]+?```", "", raw_mdcontents)
         allmatches = re.findall(r"^(#|###)\s+(.*)", parsable_mdcontents,
@@ -58,7 +58,7 @@ def api_index():
             contents += (indent + "* " + "[%s](%s)\n" % (title, link))
     indexfile = os.path.join(API_DIR, "API-index.md")
     with open(indexfile, "wb") as fo:
-        fo.write(contents)
+        fo.write(contents.encode("utf-8"))
     print("Created %s in %s" % (os.path.basename(indexfile), API_DIR))
     print("Done")