Add profile links if requested in post install

Refs #10271
Add Debian pre & post install scripts

Refs #10271
Only remove profile scripts if they were installed by us in RPM

Refs #10271
Use RPM_INSTALL_PREFIX0 directly in rpm maintainer scripts

Refs #10271
Fix install prefix for debian post install script

Refs #10271
Don't wipe LD_PRELOAD in startup scripts.

Refs #10271
Add LD_PRELOAD/TCMALLOC_RELEASE_RATE to MantidPlot launch script

Refs #10271
Add LD_PRELOAD/TCMALLOC_RELEASE to profile scripts

Refs #10271