Magnet transfers caused the by-progress sorting to become non-stable, as their
percentComplete() could return NaN. This patch fixes this by preferring active
downloads over magnet transfers, then sorting them by percentComplete().
This way all the qualifiers (`const`, `volatile`, `mutable`) are grouped
together, e.g. `T const* const x` vs. `const T* const x`. Also helps reading
types right-to-left, e.g. "constant pointer to constant T" vs. "constant
pointer to T which is constant".
There're places where manual intervention is still required as uncrustify
is not ideal (unfortunately), but at least one may rely on it to do the
right thing most of the time (e.g. when sending in a patch).
The style itself is quite different from what we had before but making it
uniform across all the codebase is the key. I also hope that it'll make the
code more readable (YMMV) and less sensitive to further changes.
Using QFileInfo to strip trailing slash(es) is bad when input contains non-
native paths (i.e. Windows paths on non-Windows system and vice versa) as it
may mistakenly treat the path as relative and change it in unespected way.
This refactoring is driven by the need to be able to do true queued RPC calls
(where each successive call uses the result of the previous).
Currently, such queueing of requests is done by assigning them special "magic"
tag numbers, which are then intercepted in one big switch() statement and acted
upon. This (aside from making code greatly unclear) effectively makes each such
queue a singleton, because state passing is restricted to global variables.
We refactor RpcClient to assign an unique tag to each remote call, and then
abstract all the call<->response matching with Qt's future/promise mechanism.
Finally, we introduce a "RPC request queue" class (RpcQueue) which is built on
top of QFutureWatcher and C++11's <functional> library. This class maintains
a queue of functions, where each function receives an RPC response, does
necessary processing, performs another call and finally returns its future.
