Basic class setup

Creating a class to facilitate interaction with plist files.
Nonfunctional daily update

Need to finish adding the ability to write values by type.
Multi-option values will not be supported.
PlistEditor Functional

The PlistEditor now works well as an easier alternative to a bunch of
subprocess.check_output calls to the defaults command.
Merge pull request #15 from univ-of-utah-marriott-library-apple/plist-editor

Plist editor