util cleanup

[debris]

• removed unused util/squeeze.rs
• removed unused util/json_aid.rs
• removed util/json-tests module. It was originally created by me as a replacement for ethereum / tests.
  • there is just one test worth keeping there. it's util/json-tests/json/trie/branching.json
• few simplifications in triehash.rs iterators (7 lines added)

[gavofyork]

are these not the standard json tests that all trie implementations check against?

[debris]

are these not the standard json tests that all trie implementations check against?

They are. I forgot about that. We can safely remove everything then :)

[gavofyork]

only if they're still checked from the standard tests. and i don't think they are.

[debris]

I've added util/json-tests/json/trie/branching.json test to triedbmut.rs in 321b16c. I think it's sufficient.

[gavofyork]

i'd prefer to keep the standard ethereum trie tests for completeness.

they are part of the cross-client consensus tests suite and i see no reason to remove.

[debris]

Removed files are not a part of cross-client consensus tests. We never used cross-client consensus tests for trie, cause these tests are placed in 6 json files written in 3 different formats. Instead of using them directly I unified their format and placed them in util/json-tests/json/trie directory (it was back in December last year). This pr is moving these tests to the code.

We could add a module for parsing and running cross-client consensus tests, but imo it should not be a part of this pr

[gavofyork]

This pr is moving these tests to the code.

only additional tests i see are the long random strings. where have those consensus-derived tests been moved to?

[debris]

All trie tests from ethereum/tests looks quite random. Anyway I've added a module, which is running all of them. link