Simplify more after removing inline types.
Starting on dynamic message manipulation (manipluating messages without knowing the schema, or without compiling in the schema).
Restore ability to upgrade from List(Bool) to List(T) where T is a struct whose @0 field is of type Bool.  I previously disallowed this to reduce complexity, but it turned out to actually increase complexity.
Various stuff in support of dynamic API.
Various refactoring and cleanup.
Simplify generated code by using PointerHelpers templates.
Dynamic API WIP.
More dynamic API WIP.
Dynamic API mostly done...  not tested.  This commit actually starts embedding the schema data in the generated code.
Allow automatic conversions between numeric types in DynamicValue.
Revamp dynamic struct getters/setters to not distinguish unions.  Add converience versions that take string names.
Schema convenience interface.
Refactor dynamic API using new schema API.
Test Dynamic API.
Fix up Makefile.am.
Remove no-longer-needed index field from schema.capnp.
Better check that schema matches exactly here.
Tweak preconditions in dynamic.c++.
Add a test.
Allow dynamically setting enum values using text literals.