The output file used for memory checker runs must be unique for every test run
in parallel, so simply make them unique for every test run. Simply use the test
index to avoid collisions.
Both <string> and <cmSystemTools.h> include <stdio.h> one or the other way. It
looks like the CMake header adds a define that will cause another part of the
system header to be used, resulting in conflicting definitions.
The dummy memory tester implementation now understands the command line
switches for all memory checkers to redirect the output to a file. This avoids
triggering the error cases for BoundsChecker and Purify because the output file
does not exist.