Windows-compatibility: Thumbnail generation (Compound Solution Pack)

Some Windows-incompatibilities have crept into the Islandora codebase ([additional background can be found here](https://groups.google.com/d/msg/islandora/0MAhLDjbago/9knbOynlyIcJ "Islandora 7 and Windows: Patches and Tips")).

Windows will sometimes write temporary data to a temp directory rather than to straight memory (this was a [necessary change to the Tuque library](https://github.com/Islandora/tuque/pull/83 "Windows-compatibility: Problems with php:// I/O streams")). As a result, the code that generates the thumbnail needs to be updated in two ways:
*  **Thumbnail name:** The colon in the object ID needs to be replaced with an underscore in the filename, since the [colon is a forbidden character in Windows paths](http://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx#naming_conventions "Naming Files, Paths, and Namespaces (Windows): Naming Conventions"). Using it results in the following error: `Warning: filesize(): stat failed for <PATH TO TEMP DIRECTORY>/islandora:XX_TN.jpg in CurlConnection->putRequest()`
* **Double-quotes:** The path `temporary://{$child->id}_TN.{$ext}` only works when it is enclosed in double-quotes. When single-quotes are used, the variables aren't interpreted, resulting in the error: `The file {$child->id}_TN.{$ext} cannot be found.` [[Reference](http://stackoverflow.com/a/14046850 "Curly braces in string in PHP")]

*NOTE 1:* The [Islandora Paged Content module](https://github.com/Islandora/islandora_paged_content/pull/42 "Windows-compatibility: Thumbnail generation (Islandora Paged Content)") is experiencing the same problem.
*NOTE 2:* The function *islandora_deployed_on_windows()* is introduced here: https://github.com/Islandora/islandora/pull/450