Release 0.7.10

• Fix a case where the #[bitflags] macro would access the crate through enumflags2::... instead of ::enumflags2::.... This makes the generated code more robust and avoids triggering the unused_qualifications lint. (#58)
• Rework the proc-macro to use syn with the derive feature (as opposed to full). This reduces the cargo build time for enumflags2 by about 20%.