When using logger with std::size_t, should use "%ld" not "%d"

[Chris Richardson]

In various places there are lines like:

std::size_t M, N;

info("Solving linear system of size %d x %d (PETSc Krylov solver).", M, N);

which results in incorrect output (negative numbers) when M or N are > 2^31.

Replace %d with %ld.

[Patrick Farrell]

Partially fix issue 314.

→ <<cset beaec69564f8>>

[Chris Richardson]

Reopen until fully resolved/merged

[Chris Richardson]

Added a few more %ld - I'm sure there are more to be found.

[Prof Garth Wells]

Removing milestone: 1.5 (automated comment)