[gemspec] (GH-82) include all files in gemspec

The gemspec was only pulling in files in the bin, lib, and spec dirs,
which works fine for packaging as a gem but makes it more challenging to
repackage r10k in other format. This commit rectifies this by packaging
all files managed by git, which is what a number of other ruby projects
do.
Merge branch 'issue/master/gh-82-include-all-git-files'

This closes GH-82.
[LICENSE] Update copyright year to 2014

It's 2014, where's my hover skateboard!?
Update version and CHANGELOG for 1.1.3