Before, this was comparing, for example, `.text-2`
with `.text-10` with standard string comparison,
yielding `.text-10` before `.text-2`.
Instead, this simply uses a stable sort by name,
which preserves the relative ordering of sections.
Implements MIPS relocation pairing logic.
New option for "Register '$' prefix", off by default.
Fixes various regressions introduced by refactoring.
Resolves#122Resolves#156
