This change updates our urfave/cli dependency to the v2 branch of the library.
There are some Go API changes in cli v2:
- Flag values can now be accessed using the methods ctx.Bool,
ctx.Int, ctx.String, ... regardless of whether the flag is 'local' or
'global'.
- v2 has built-in support for flag categories. Our home-grown category
system is removed and the categories of flags are assigned as part of
the flag definition.
For users, there is only one observable difference with cli v2: flags must now
strictly appear before regular arguments. For example, the following command is
now invalid:
geth account import mykey.json --password file.txt
Instead, the command must be invoked as follows:
geth account import --password file.txt mykey.json
This commit adds pluggable consensus engines to go-ethereum. In short, it
introduces a generic consensus interface, and refactors the entire codebase to
use this interface.
