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
Did two things to stop the crash. 1. When following an address path if we hit a NULL
address, stop processing and return the NULL. 2. When trying to resolve addresses in
copy_sim_data, if a NULL address is returned then reset the reference to unresolved and
return a dummy value.
Need to fix MTV to handle dummy value returns.
refs #117
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.
