OUT-OF-SOURCE BUILD

1) Change the extra/CMakeLists.txt to build the innochecksum as per user
   defined build option.
2) Removed the --debug option for non-debug build of innochecksum.
3) Created new test, innodb-wl6045-debug.test which will run only on
   innochecksum build in debug.

Approved by Kevin, Mattiasj rb#2531