From: Feiynag Xue <fxue@roku.com>

P4 allows non-unicode characters in changelist description body,
so git-p4 needs to be character encoding aware when reading p4 cl

This change adds 2 config options, one specifies encoding,
the other specifies erro handling upon unrecognized character.
Those configs  apply when it reads p4 description text, mostly
from commands "p4 describe" and "p4 changes".

Signed-off-by: Feiynag Xue <fxue@roku.com>

Submitted-As: https://lore.kernel.org/git/pull.864.git.1612371600332.gitgitgadget@gmail.com