* Fix conformance running nothing issue

This change adds a source dependency of the test suite implementaion
class in the main function. For generality reason, the main function is
moved to the file of the test suite implemetation.  New test suite
implementation will need to implement the main function.
In order to make it easy for test suite implementation to implement the
main function, this change also refactor out the common code out of the
main function.

* Fix typo

* Give a unique category to each test.

This change introduce a TestCategory enum to ConformanceRequest. Existing tests
are divided into three categories: binary format test, json format test and json
format (ignore unknown when parsing) test. For the previous two categories, there
is no change to existing testee programs. For tests with the last category, testee programs
should either enable ignoring unknown field during json parsing or skip the test.

* Fix python test

* Fix java

* Fix csharp

* Update document

* Update csharp generated code

* Enable ignoring unknown in json parsing in php

* Update generated descriptor files

* Update failure list for other languages.

* Remove unnecessary php files

These statements pulled a bunch of symbols from the std namespace into
the global namespace. This commit removes all of them except for
std::string, which is a bit trickier to remove.

* Reserve unknown in ruby

* Revert ruby tests. Wait for cpp impl for conformance test

* Add conformance test for preserving unknown

* Add unknown field conformance test to csharp failure list.

* Fix comments

* Fix comment

* Fix comments

* Fix typo

* Use stringsink_string directly

* Mark hd unused

* Remove unused encodeunknown_handlerfunc

* Remove using std::{set,map}

* Fixed a bunch of Ruby conformance errors.

* Fixed some more Ruby conformance errors in JSON.

About 1.5% of all IEEE754 single-precision numbers require nine
decimal digits to represent accurately.

* A few more cases for binary conformance tests.

* over-encoded varints (encoded in more bytes than are necessary).
* truncated varints (>32 bits for 32-bit types).

* Fixed Python decoding bug with 32-bit varints.

* Fixed 1L -> 1LL for 32-bit platforms.

This is basic and more tests will be added over time.

* Factored Conformance test messages into shared test schema.

* Updated benchmarks to use new proto3 message locations.

* Fixed include path.

* Conformance: fixed include of Python test messages.

* Make maven in Rakefile use --batch-mode.

* Revert changes to benchmarks.

On second thought I think a separate schema for
CPU benchmarking makes sense.

* Try regenerating C# protos for new test protos.

* Removed benchmark messages from test proto.

* Added Jon Skeet's fixes for C#.

* Removed duplicate/old test messages C# file.

* C# fixes for test schema move.

* Fixed C# to use the correct TestAllTypes message.

* Fixes for Objective C test schema move.

* Added missing EXTRA_DIST file.

Add note about JSON tests maybe being wrong.

- Add note about the JSON test maybe not being correct yet.
- Add test to checks the generated names for double underscores to be sure they
  are what is expected.

- String behaviors
- Testing only valid JSON is allowed

Add more JSON tests around underscores

Incase the different runtimes have different generation/implementations for
for the different primitive field types, cover a larger range of the proto
types in the oneof zero tests.

* Add conformance test for zero fields in oneofs.
* Add failures to the "expected" files.

can reasonably be expected to be interoperable.

(The fact that not all Int64/Uint64 values *can* be exactly represented in
IEEE-754 and thus interoperably amongst JSON implementations is precisely the
reason for wrapping them when we serialize... it shouldn't be a surprise that
we can't round-trip in unwrapped form for all values.)

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

- Update all the new runner cases to handle a skip result as a skip and not a failure.
- Make ObjC use the new serialize_error result if it fails to generate the data.

commit e841bac4 seems to have mis-merged the
change to reporting skipped tests.

I didn't check if there were other merge issues.