According to #61, if one uses serde to serialize requests that pass
url-encoded parameters to a server, it might get responses back
with a different capitalization scheme. This patch restores the
behavior implemented in #62.
# Conflicts:
# serde_codegen/src/attr.rs
# serde_codegen/src/de.rs
# serde_tests/tests/test_annotations.rs
This feature has never been used, and it's complicating the
implementation of #207. We could restore this functionality if there is
ever interest in it.
Closes#211.
