* spot/priv/allocator.hh, spot/priv/Makefile.am: add a STL-compliant
allocator based on spot::fixed_size_pool
* spot/misc/fixpool.hh, spot/misc/fixpool.cc, spot/misc/Makefile.am:
refactor the existing spot::fixed_size_pool
* spot/ltsmin/ltsmin.cc, spot/twa/twaproduct.cc: reflect changes in the
interface of spot::fixed_size_pool
* tests/core/mempool.cc: test the new allocator
Annotate pools with valgrind macros so that it detects errors in pool
usage. Typically, we wish valgrind to detect a leak when the user fails
to call proper deallocation function.
* spot/misc/fixpool.hh, spot/misc/mspool.hh: here
* configure.ac: ensure that valgrind header exists
* tests/Makefile.am, tests/core/mempool.cc, tests/core/mempool.test,
tests/core/.gitignore: add tests to ensure valgrind accurately detects
leaks
