v0.5 - Output formatters

Use a -> to direct Equator to format outputs in a specific way. Available formatters:

• num: All values as a number (eg. 2*pi -> num = 6.283185...)
• sci: All values as scientific notation (eg. 10.35 -> sci = 1.035e+2)
• dec: All values as decimal numbers (ie. not scientific notation)