Add Comments and rework entry_range method
Add Comments and rework entry_range method

The entry_range method has been reimplemented in a more straightforward manner and
comments added.

Operators used for concatenation of cache entries with recursive calls to bread_cached
have been modified and commented for clarity.

rsevilla87/manageiq-gems-pending,aljesusg/manageiq-gems-pending,aljesusg/manageiq-gems-pending,rsevilla87/manageiq-gems-pending