Added blocks to prevent automatic scientific notation or infinity con…

[esophagoose]

I noticed a bug in where this: (tedit 5E888720) parsed to [Symbol("tedit"), inf]

This is because the parser tries to convert to a float and there's many expressions that are valid for the constructor of the Python float. It was determining "5E888720" as 5*e^888720. This PR blocks the float conversions that aren't part of the S-expression spec. According to Wikipedia, valid s-expression datatypes are:

Lists and pairs: (1 () (2 . 3) (4))
Symbols: with-hyphen ?@!$ |a symbol with spaces|
Strings: "Hello, world!"
Integers: -9876543210
Floating-point numbers: -0.0 6.28318 6.022e23

I also added unit tests

[jd-boyd]

Since you reference Wikipedia, could you please add a link to the referenced page in a comment.

Also, would you mind adding test cases for the wikipedia float examples used: -0.0 6.28318 6.022e23

I that that you will find the last one doesn't work with your approach to fixing this and it probably should.