packagekit: fix using free instead of delete[]. CID 1210827.

package daemon: FSUtils::OpenSubDirectory(): Make param const

package daemon: ExtractPackageContent(): Extract only requested

... content path.

package daemon: Implement writable files handling

* Move Volume::Exception to top level and into own files.
* Add utility class FSUtils, move Volume::RelativePath there and add a
bunch of FS utility functionality.
* Add FSTransaction, a helper class to record FS operations and revert
them.
* When activating a package we now extract the writable
files/directories it declares. The handling is not quite complete:
- We don't handle merges yet. I.e. the user will have to do that
manually for now.
- We don't propagate issues/infos regarding the writable files (e.g.
that a manual intervention is required) to the user yet.

packagekit: fix using free instead of delete[]. CID 1210827.

package daemon: FSUtils::OpenSubDirectory(): Make param const

package daemon: ExtractPackageContent(): Extract only requested

... content path.

package daemon: Implement writable files handling

* Move Volume::Exception to top level and into own files.
* Add utility class FSUtils, move Volume::RelativePath there and add a
bunch of FS utility functionality.
* Add FSTransaction, a helper class to record FS operations and revert
them.
* When activating a package we now extract the writable
files/directories it declares. The handling is not quite complete:
- We don't handle merges yet. I.e. the user will have to do that
manually for now.
- We don't propagate issues/infos regarding the writable files (e.g.
that a manual intervention is required) to the user yet.