* refactor: make variant_headers reusable to qt app.
Torrent.cc's `change()` template methods are generically useful to deal
with tr_variant wrangling, but previously were only used in Torrent.cc.
This PR moves them into a new API `VariantHelpers.h` for use by Prefs,
Session, TorrentModel, etc.
* refactor: use snake_case field naming in qt client
* fix: some missed symbols
* chore: make uncrustify happy
* fixup! refactor: use snake_case field naming in qt client
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.
Split FileTree.{h,cc} and FilterBar.{h,cc} files so that each class
is in its own file.
This breaks translations (some classes got renamed => context changed),
to be fixed by next commit (along with Tx sync).
