[Issue #23] Allow larger than 2GB files to be read.

[jwkblades]

read and write return a signed int, meaning that they can only read up to 2 billion bytes (2GB) at a time. bsdiff and bspatch were expecting the entire file to be read (or written, respectively) in a single call to read or write, which is only possible if they are less than 2GB in size. There are also other times in which a single function call would be inadequate for IO, for instance in the case where a device is busy. The fix for this was to place the functions in a loop and continue as long as at least 1 byte was transferred (in or out). If an error, or 0 return value, comes back from the transfer, break out of the loop and return the total number of bytes that had been transferred up to that point.

Updated the .gitignore file to ignore vim swap files, as well as the autoconf (generated) files and the executables.

[gaetandezeiraud]

Thanks for the Pull Request. I integrated it into the project bsdiff-nodejs (https://github.com/Exoway/bsdiff-nodejs).