File header

### Features:
#### File Header
##### Properties:
* File Name
* Plain-text data hash
* Compressed plain-text data Hash
* Part Number
* Total Parts
* Compressed flag
* Header version information

##### Functions:
* Read Header - Reads the values from the header
* Write header - Writes the header values to the file
* Remove header - Removes the header from the file

#### Other:
* SHA1 hashing function for files
* FileReader class - Easily read blocks of bytes