Data-injection and valgrind checking for the XFS PMDA

Adds support for injecting canned data into the Linux XFS PMDA
for testing purposes.  Marks recent test (qa/987) is extended
to use this mode, such that metric values are further verified.

Additionally test qa/988 is added which performs valgrind-based
memory access checking on the PMDA when valgrind is available.
python api: int vs long type regression from py3 work

Resolve a type issue picked up by qa/702 and qa/707, fallout
from recent python3 porting work.  We must continue to use an
int type in the symbol dictionaries because these are exposed
above the API - when passed in certain places, if an int has
not been used ctypes conversions fail (python3 has no int, it
is all longs internally - mirrored in the C API).
Set pmdamemcache refresh rate to improve qa/835 determinism
Add QA archive mysql-1.0 into the installed set