Major revision of interface and bug fixes

• Firefly is now called by the script firefly.py (or firefly_sdss.py, firefly_manga.py). All parameters are set through this one wrapper.
• Cap on the maximum number of fit objects to be created per iteration removed, as in some cases it generated a bias in templates files used.
• MaStar models added and some versions of M11 model and BC03 model removed as not working.
• Wavelength dependent instrumental resolution added.
• Improved functionality of emission line masking and masking of individual pixels
• Output reset to model fit in observational data wavelength range