Handle spaces in arguments and executable path

[kodemeister]

This PR fixes #10 and also supersedes #8. Unlike #8, it doesn't bring boost::algorithm dependency to the shim code, keeping it small and lightweight. If the changes look good to you, feel free to merge them and close #8.

[mnivet]

In fact the shim code already has a dependency on boost::algorithm, because it use the resources.cpp code from shmake.
See here : https://github.com/aloneguid/win-shim/blob/master/shim/shim.vcxproj#L154

And that file depends on boost/algorithm/string.hpp
see here : https://github.com/aloneguid/win-shim/blob/master/shmake/resources.cpp#L5

But your solution is still better than the one I’ve come with, so I will close my PR, since i’ve now merge your solution into my personal branch.