* Update `add_license` script
* run script
* add `remove duplicate lines script` and run it
* Revert changes `English spaces`
* strip whitespaces
* Revert `GPL` in files with `apache/mit license`
* don't append `gpl license` in files with other lic
* Don't append `gpl header` in files with other lic.
* re-ran script
* include c and cpp files too
* remove duplicate header
* rebase nit
* rlp::decode returns Result
* Fix journaldb to handle rlp::decode Result
* Fix ethcore to work with rlp::decode returning Result
* Light client handles rlp::decode returning Result
* Fix tests in rlp_derive
* Fix tests
* Cleanup
* cleanup
* Allow panic rather than breaking out of iterator
* Let decoding failures when reading from disk blow up
* syntax
* Fix the trivial grumbles
* Fix failing tests
* Make Account::from_rlp return Result
* Syntx, sigh
* Temp-fix for decoding failures
* Header::decode returns Result
Handle new return type throughout the code base.
* Do not continue reading from the DB when a value could not be read
* Fix tests
* Handle header decoding in light_sync
* Handling header decoding errors
* Let the DecodeError bubble up unchanged
* Remove redundant error conversion
* WIP
* Convert Ethcore error to use error_chain
* Use error_chain for ImportError and BlockImportError
* Fix error pattern matches for error_chain in miner
* Implement explicit From for AccountsError
* Fix pattern matches for ErrorKinds
* Handle ethcore error_chain in light client
* Explicitly define Result type to avoid shadowing
* Fix remaining Error pattern matches
* Fix tab space formatting
* Helps if the tests compile
* Fix error chain matching after merge
