1. Implemented HTTP server to support web3.js API in iotex-core (this removes the need of intermediate Babel bridge/service)
2. Added eth_getStorageAt method
3. Instrumented tracing to measure timing on critical code path
4. Enabled EVM tracing to collect calling stacks inside EVM
5. Performance improvement of ActPool
6. Enabled log rotate
7. Corrected nested context usage in transaction processing loop