Slamtec RPLIDAR Public SDK for Rust v0.6.0

• improve: rewrite rpos_drv::Error with quick-error crate
• improve: the structure of the project

Slamtec RPLIDAR Public SDK for Rust v0.5.0

• new feature: rplidar_drv::sort_scan (ascendScan in C++)
• reform: renamed rplidar_drv::protocol::RplidarProtocol to RplidarHostProtocol
• improve: eliminated dependency to libudev to avoid cross compile failure on linux