TODO v0.1.0

[shrektan]

• [ ] more tests for date part functions
• [ ] probably different API for date part functions to avoid name conflicts
• [ ] a vignette on performance
• [ ] parallel?
• [x] better error handling (now on error, it reports rust panicked with the real message being thrown to stderr instead of the r's stderr) - Not very satisfied the solution, but it's much better now
• [ ] package size on CRAN's mac build (sometimes it contains a debug file, which is 5MB and looks useless to me)