Fixes #196

Bug fix rollup for 0.6 release

Fixes #212

Specifically, consider:

    capnp::BuilderFor<capnp::DynamicStruct> capnp::Orphan<capnp::AnyPointer>::getAs<capnp::DynamicStruct>(capnp::StructSchema)

Note that `BuilderFor` is a "template using" directive which expands into something more complicated.

GCC mangles the symbol as:

    _ZN5capnp6OrphanINS_10AnyPointerEE5getAsINS_13DynamicStructEEENS_11BuilderFor_IT_Xcl4kindIS6_EEEE4TypeENS_12StructSchemaE

Which `c++filt` decodes as:

    capnp::BuilderFor_<capnp::DynamicStruct, (kind<capnp::DynamicStruct>)()>::Type capnp::Orphan<capnp::AnyPointer>::getAs<capnp::DynamicStruct>(capnp::StructSchema)

Note that `BuilderFor_<...>::Type` here ends up being a typedef for `DynamicStruct::Builder`. It seems weird to me that the symbol name would not substitute this typedef.

Clang, meanwhile, mangles the symbol as:

    _ZN5capnp6OrphanINS_10AnyPointerEE5getAsINS_13DynamicStructEEENS_11BuilderFor_IT_Xclgssr5capnpE4kindIS6_EEEE4TypeENS_12StructSchemaE

Which `c++filt` does not seem to be able to demangle at all. But, it looks like `capnp::kind` is in there, suggesting that, again, the typedef wasn't substituted.

I don't know who is right, but if we inline the whole thing, the problem goes away.

Fixes #251

Fixes #336

Fixes #363.

Fixes #403

Fixes #405

Fixes #435

Fixes #456

Configure Travis CI for Linux and OSX builds.

This is redundant since branches are usually open in order to become PRs, which get their own merged-with-master builds.

fix typo in comment

Fix bug where struct equality could ignore some pointer fields.

fix copy-pasto in recently-added test case

update method names in error messages

Fixes #174

adjust AnyList::equals(): a list of pointers cannot be equal to a struct list

I did run them once and they passed. It took a very long time.

Otherwise, the HTTP client might be destroyed before it has written all data, since the responses have already been received.

In particular this fixes http-test on Win32.

Add initial AppVeyor support

canonicalization: make sure that pad bits of primitive lists are zeroed

ignore pad bits when checking for bit list equality