* all: add read-only option to database

* all: fixes tests

* cmd/geth: migrate flags

* cmd/geth: fix the compact

* cmd/geth: fix the format

* cmd/geth: fix log

* cmd: add chain-readonly

* core: add readonly notion to freezer

* core/rawdb: add log

* core/rawdb: fix freezer close

* cmd: fix

* cmd, core: construct db

* core: update tests