only remove wave file header if present

[mogrifier]

Need to test for header- examine first few bytes and look for WAVE. Also, why do I have 32bit floating point files with 100 byte headers? Normal or not?

[mogrifier]

added isWaveFile function to look at start of file for header data (RIFF). This identifies wav file BUT makes assumptions about header length. 44 for all files except 32 bit, which I am using 100 for since only files I have seen have a 100 byte header.