Solve issues when compilerFile has spaces

Solve an issue that occurs when the given path to the compiler file has
spaces.

For example, if you set compilerFile = 'my path/compiler.jar', the
command
to be run on the shell would be:

jar my path/compiler.jar ...

...which is obviously incorrect.
Merge pull request #4 from tgirardi/solveSpacesInCompilerFile

Solve issues when compilerFile has spaces