The values of droption accumulated options are not reset on detach, causing them to accumulate in a statically-linked client.
There is no control point for droption to do this automatically, so we add droption_parser_t::clear_values() that a client can call.
Adds a call to clear_values() in drmemtrace.
Augments the drmemtrace burst_malloc test to fail when the options are not reset (i.e., fail without this fix). This serves as a test of the new feature, as the existing droption tests do not have static clients nor simple ways to add re-attaches.
Adds a section to the droption documentation explaining the new feature.
Fixes #4139 (closed)