(CFACT-124) Refactor memory resolver into a sharable base.

Refactoring the memory resolver into a common base implementation.  The
base implementation is responsible for the fact definition while the
child types are responsible for collecting the data.
(CFACT-124) Refactoring operating system resolver.

Refactroing the operating system resolver into a base that is
responsible for adding the facts and child types that are responsible
for collecting data.  This allows it to be shared with Windows.
(CFACT-124) Refactor uptime resolver to shared base.

Refactoring the uptime resolver into a shared base implementation that
is responsible for defining the facts while the child types are
responsible for collecting the data.
(CFACT-124) Refactor timezone resolver into base implementation.

Refactoring the timezone resolver into a base implementation that is
responsible for adding the facts and child types that are responsible
for collecting data.