Interval calculation

[analogikaHH]

Working on a script to calculate the interval, in cents, as well as semitones ±50 Cts., between two user-supplied frequencies.

Also includes a tool to identify nearest pitch tone, relative to concert pitch.

Pitch identification should probably be broken out into separate script?

[TimZiemer]

These are useful features. Please create two separate functions for interval calculation and pitch identification and allow users to call the function passing the one (for pitch identification) or two (for interval calculation) frequencies as variables. I've created a new branch for this feature.