Whitespace changes by clang-format.

These files are the ones with the least number of changes when running
clang-format over them and only the less controversial changes are
included, with a preference for having stay the same where things are
likely to be more controversial.
I've tended towards two lines between adjacent blocks of visibility (public/protected/private) or function (slots / signals) {and at least one line between method declarations (first) and members (second) - and given the chance, I'd group all the method declaration before all the members in such blocks.}  Anyone else have a different opinion to this?