v0.5.0

• finished implementation of the SII (Slave Information Interface), providing informations about the capabilities and options of the slaves
• added topic reservation through RawMaster::topic, allowing to send new frames without waiting for each answers and improving realtime cycles
• a mailbox can now be initialized on any Sync Channel (as long as the slave supports it)
• tested in production on Omron and Synapticon servodrives
• fixed Cargo.toml parsing error