ASCII Test Changes

Changes Made:
In send file
1)Removed the arbitrary pattern of pulses
2) Added methods to convert string of text into a pulse train
3) Kept method of 38KHz modulation

In receive file,
1) Removed serial output of OFF and ON pulses
2) Wrote ways to convert pulse trains into binary string
3) Wrote ways to read from binary string and convert into ASCII
characters
4) Kept method of receiving pulses