CMake Fix up prerelease version handling

JS: import well-known types from google-protobuf package.

- Better docs in the generator for the different options that can be passed
  during an invoke of protoc.
- Add named_framework_to_proto_path_mappings_path to pass the path to a file
  containing mappings of frameworks for different proto files.
- Update the generation to use the mapping to change the #import directives
  it creates.

Note: the changes in helpers is mostly moving code within the fine, and then
a small change to expose the parsing so a passed on class can consume the line.

Fixes https://github.com/google/protobuf/issues/1457

Workaround for gcc-4.4 incompatibility

constructor, and instead create an _internal_only getter
that gets the needed information. This is a workaround for
a deficiency in gcc-4.4 that does not properly support
templated friend classes.

Cleanup protobuf-module.cmake.in

CMake package requirements

Add support for generation sources into a framework.

- Add a protoc objc option (generate_for_named_framework) to set the name of
  the framework all generated sources will be in.
- Tweak some comments/naming to make it clear what is the Protobuf framework
  vs. the framework for generated code.
- Update the objc README to document the new generation option to protoc.

This is working towards https://github.com/google/protobuf/issues/1457.

Also hotwires updating ruby as CocoaPods was crashing within a support library.

Fixes #1619 

proper codeblock in README

protoc: support '=' in --proto_path arguments

CMake prerelease versioning

Build examples in CMake

Make conformance tests more strict about the failure list.

OS X's version of Python has a slightly different error
message for this error case.

A series of improvements:

- Improved Protobuf module compatibility (disabled by default);
- Hide advanced settings;
- Added build tree configuration;
- Added build of examples.

Python 2.x doesn't detect unpaired surrogates so we have to
do that manually.

The failure lists were falling out of date because the
tests would pass even if people forgot to remove failures
from the list.

Add more context to GPBCodedInputStream failures.
Have GPBMessage parsing apis extract out the GPBCodedInputStream information and expose it.
Update HeaderDocs with pointers to all error domains/codes.
Expand the unittests to cover the full set of errors reported.

Fixes https://github.com/google/protobuf/issues/1618