Fix installation for read-only files.

On Windows, we must explicitly add write permissions to the target
file before removing it, as the operation will fail if the file is not
writable.

Task-number: QBS-475
Change-Id: Ide40cc4310e327265b0a5c08f4935866762797b9
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
Fix artifact cleaner.

If the "remove all" flag is not set, we must take care to not only skip
target artifacts, but also their siblings that are not target artifacts.
Otherwise, the build graph can end up in an unexpected state.

Change-Id: Ie2fa36f3e489c3bee19f461e16fa093515b01020
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
Docs: Add documentation for convenience items.

Change-Id: I835d1ed8835577fab5434ae89c058fc710d708b1
Reviewed-by: Jake Petroules <jake.petroules@petroules.com>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@digia.com>
Merge remote-tracking branch 'origin/1.1'

Change-Id: Ic3e0027187a15fdc59faeee6fa51ebeb73828c28