Added recent official changes of the API

Revisited this bug fix to account for the recent inclusion of save_path in the AddPackage function after the pull request was flagged as a conflicting merge.
Updated API to Include Most Recent Official Changes
Partially reverted the official changes.

While the new official code removes save_path from its specific point of proper use to folder names in general. This will again strip colons and slashes from paths added via the API, mangling download paths from, for example, X:\Intended\Folder to D:\Default pyLoad Download Folder\XIntendedFolder. The prior code is clunkier but fit-for-purpose.
Mixed the official changes into the bug fix.

Mixed the recent official changes into the bug fixes for [Inconsistent Download Locations with FlexGet](https://github.com/pyload/pyload/issues/808). Looks solid. Pushing to sasese\stable and into the pull request.
Polished the fix, ready for merge. See comments.
Merge pull request #1 from sasese/test

Merge API fixes into sasese\stable for merge with pyLoad.