Release v2.7.1 with minor bug fixes

Minor bug fixes:

view commit • Fixing startup race condition bug, and adding annotation on GPU events to distinguish between different vendors when used at the same time.

view commit • Fixing lldb call

view commit • Adding header for otf2_listener Adding missing header when OpenCL and OTF2 support both enabled.

view commit • Don't detach async thread, it should be stable enough to join now even with very short running programs.

view commit • Merge branch 'develop' of git.nic.uoregon.edu:/gitroot/xpress-apex into develop

view commit • Updating version number for point release