Report a warning if the proto file doesn't have a syntax statement.
Fix Python C++ implementation build issues:
  1. Haven't included the include path for "config.h".
  2. Use of C++11 auto keyword.
Replace links in nano proto code.
Add a ./configure flag "DIST_LANG" to select which langauge to include
in a distribution package.
Get rid of some build warnings.
Merge pull request #81 from xfxyjwf/syntax_warning

Report a warning if the proto file doesn't have a syntax statement.
Merge pull request #105 from xfxyjwf/fix_92

Fix Python C++ implementation build issues
Merge pull request #111 from xfxyjwf/googlebot

Replace links in nano proto code.
Merge pull request #115 from xfxyjwf/fix_107

Add a ./configure flag "DIST_LANG".
Merge pull request #116 from xfxyjwf/fix_warnings

Get rid of some build warnings.
Explicitly list all Java lite runtime tests (and exclude those depending
TestUtil which transitively depend on the full runtime).
Make test code runnable with C++11

Preprocessor token right after string literal without whitespace results
in parse failure in C++11.
Display element name in test error log
Make C++ string oneof field compatible with C++11

string oneof field was generated into "const ArenaStringPtr" field inside
"default_oneof_instance_" struct (of name "<class name>OneofInstance").

On the other hand, in C++11, const field of type with trivial default
constructor causes enclosing type's implicit default constructor to be deleted.

Since ArenaStringPtr has tirvial default constructor, this caused default
constructor of "default_oneof_instance_" struct to be deleted, making the
constructor call inside generated code invalid and fail to compile.