the removal of `init` from `setcode` moved compilation AND validation of wasm to the first action.  We should do validation during `setcode` but doing this properly requires additional work.  This is a temporary fix

Additionally, the injector code was failing when hit with hand crafted wasm that had no types/import section(s)

Adding a few more constraints on the WASM execution environment. Some of these we’re well aware of but others are new constraints to aid performance and scalability.

* Limit initial linear memory size to 16 pages (1MB) maximum
* Limit linear memory initializers to the first page (first 64KB)
* Limit number of table elements to 1024
* Limit mutable globals to a maximum of 1KB
* Limit load/store offsets to a maximum of 1MB (matching maximum runtime size)

bugfixes in singleton, bugfixes in identity contract, more tests for identity contracts (one fails because of bug in next_primary)

back to singleton for accounts, bugfixes in db api, test for trusted owner (fails because primary_lower_bound doesn't work as I expected)

Updated the ABI, fixed implementation of `get_currency_balance` in the tester, separated out currency tests, added verification that balances are what is expected

We've made the decision that sbrk is the way contracts will grow memory. So, remove access to WASM's standardized memory opcodes. As it stood, these subverted our expected memory management.

WASM globals are disparate from WASM linear memory. Similar to how we reset linear memory after each invocation, we need to reset globals as well.