Runtime download model path encoding

[pwalski]

Models can be downloaded to a temp path with incorrectly encoded non ascii characters. It looks like some form of URL encoding.
For example "#" has been replaced with "%23%", like here:
C:\Users\username\Workspace\C%23\GamerHashAI\GamerHashAI\bin\Debug\modules\golem_0.1.7\golem-data\provider\exe-unit\cache\tmp.