(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.

Refactoring 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.

This refactoring also merges the LSB resolver in with the operating
system resolver.

Breaking change: some of the names on the os structured fact have
diverged from Facter 2.2 to clean up the less than ideal naming. We need
to investigate if this will be impactful and how to mitigate.
(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.
(CFACT-124) Refactor virtualization resolver into base type.

Refactoring the virtualization resolver into a base type that is
responsible for adding the facts and child types that are responsible
for collecting data.
(CFACT-124) Refactoring block device resolver.

Refactoring the block device resolver into a base type responsible for
adding the facts and child types that are responsible for collecting
data.