Release v0.4.8

What's Changed

• Multiple small optimizations
• Plot for precursor calibration, general optimization of the calibration
• New generic score to replace the x_tandem
• Memory optimizations
• Changed the default prec_tol to 20, default_mass_tol to 50
• #488: fix error when scoring on machines with more than 60 cpus by @mschwoer in #489

Full Changelog: v0.4.7...v0.4.8