Use kIOMasterPortDefault const instead of call to IOMasterPort()

- Since the default mach port is being used, no need to call **IOMasterPort()**, use
  global constant **kIOMasterPortDefault** instead. See references below
- Add .gitignore for project executable
- Add original Apple SMC tool author name to README

##### References about kIOMasterPortDefault

- [IOKitLib.h](https://developer.apple.com/library/mac/Documentation/IOKit/Reference/IOKitLib_header_reference/Reference/reference.html#//apple_ref/doc/uid/TP40012419-CHIOKitLibhConstants-SW2)
- [Apple Mailing List](http://lists.apple.com/archives/darwin-development/2002/Aug/msg00160.html)
- [OS X and iOS Kernel Programming](http://books.google.ca/books?id=_CUbHkTNXIcC&lpg=PA360&ots=UlxKXGm0Ho&dq=kIOMasterPortDefault&pg=PA73#v=onepage&q=kIOMasterPortDefault&f=false)