Backporting addition to suspend accepting new variable server connections and
all communications to variable server clients for the duration of reloading
a checkpoint
refs #168
Back ported validate_address fix from trunk.
Added a flag called validate_address to each variable server thread. When
activated each pointer address will be tested to see if it is in memory
the memory manager is tracking. If it is then everything proceeds normally.
If it does not, then an error return value is returned for the value of this
variable.
refs #193
Changed all header file once include variables to follow the same naming
convention and not start with any underscores. Also deleted old
incorrect copyright notices. Also removed $Id: tags from all files.
Fixes#14. Fixes#22.
