Fix typos in README.md

Updated python examples to use with.

Fixed unused parameters and extra ';'

make 'no syntax' warning useful by showing which file

nuspec dependency fixes

Clarified that 'nmake' must be run before 'nmake check'.

Fix Intel compiler warnings in include files on Windows

Check in strong name key.

Added support for binary gems.

Explicitly don't add any dependencies for "old" platforms, to avoid unnecessary
dependencies in those cases.

Fixes issue #1203.

Few fixes.

Enable JavaScript tests for binary parse/serialize.

Rename Preconditions to ProtoPreconditions

(Generated code changes in next commit.)

Rename GeneratedCodeInfo to GeneratedClrTypeInfo

Recently, descriptor.proto gained a GeneratedCodeInfo message, which means the generated code conflicts with our type.
Unfortunately this affects codegen as well, although this is a part of the public API which is very unlikely to affect hand-written code.

Generated code changes in next commit.

Clarify readme for C#

These should have been included in the first match
but I overlooked them.

This involved deleting some of the code that tests
Google-internal-only features.

Make protobuf Skylark extension appends the workspace root

Manually down-integrate python JSON struct support from internal code base.

Integrate google internal changes to master

Java files are moved to un-do the hack in the prevous commit, which
moved the java files to the original position for integration.

Moving the files to their original location, so that opensource changes
can be picked during the internal merge. Those files will be moved into
the correct location after merging with internal code.

Note: do NOT merge this into master without the other internal
down-integration commit.