* core,eth: add empty tx logger hooks
* core,eth: add initial and remaining gas to tx hooks
* store tx gasLimit in js tracer
* use gasLimit to compute intrinsic cost for js tracer
* re-use rules in transitiondb
* rm logs
* rm logs
* Mv some fields from Start to TxStart
* simplify sender lookup in prestate tracer
* mv env to TxStart
* Revert "mv env to TxStart"
This reverts commit 656939634b9aff19f55a1cd167345faf8b1ec310.
* Revert "simplify sender lookup in prestate tracer"
This reverts commit ab65bce48007cab99e68232e7aac2fe008338d50.
* Revert "Mv some fields from Start to TxStart"
This reverts commit aa50d3d9b2559addc80df966111ef5fb5d0c1b6b.
* fix intrinsic gas for prestate tracer
* add comments
* refactor
* fix test case
* simplify consumedGas calc in prestate tracer
* all: mv loggers to eth/tracers
* core/vm: minor
* eth/tracers: tmp comment out testStoreCapture
* eth/tracers: uncomment and fix logger test
* eth/tracers: simplify test
* core/vm: re-add license
* core/vm: minor
* rename LogConfig to Config
