Ready TraceR for spack

• Bug fixes
• Implementation of scatter
• Simplify the build system for spack package

Re-license

• Re-license TraceR as MIT

Major Release 2.0

• Move to C++
• Support for OTF2 trace input
• Ability to replace message sizes per job
• Ability to loop over a part of the trace
• Implementations for collectives and MPI protocols