Fix non-ASCII characters + add Chocolatey-Version tests

Chocolatey-Version.ps1 uses dash characters that are not standard ASCII minus signs, but Unicode "en" dashes (probably caused by copy-pasting from a word processor) in command invocations. The Powershell parser actually handles it, but some text manipulation tools have problems.

InstallChocolatey.ps1 contains an invalid sequence of bytes that once represented the copyright character, but got corrupted. Replace it with plain ASCII "(c)".

Also add some smoke tests for Chocolatey-Version.