* tx combinators now take operate on Result to allow for more robust errors handling
replace with_fee() and with_lock_height() with a more flexible with_features()
* pass kernel features in as arg to build::transaction()
* fix chain tests
* fix pool tests
* do not pass kernel around in the combinators
just set it once on the tx when building
* build::partial_transaction now takes a existing tx to build on
* maintain header_head as distinctly separate from head
* cleanup corrupted storage log msg
* simplify process_header and check_header_known
* remember to commit the batch when successfully processing a header...
* rework sync_block_headers for consistency with process_block_header
* cleanup unrelated code
* fix pool tests
* cleanup chain tests
* cleanup chain tests (reuse helpers more)
* cleanup - head not header on an extension
shortcircuit "rewind and apply fork" for headers if next header
* always stem local txs if configured that way (unless explicitly fluff from wallet)
this overrides current epoch behavior for txs coming in via "push-api"
rename "local" to "our" txs
* TxSource is now an enum for type safety.
* dynamically resize lmdb
* rustfmt
* explicitly close db before resizing
* rustfmt
* test fix
* rustfmt
* pool tests
* chain fix
* merge
* move RwLock into Store, ensure resize gives a min threshold
* rustfmt
* move locks based on testing
* rustfmt
