dxt_analyzer

See merge request !16

- match convention of other modules where possible
- avoid trampoline for non-PMPI calls
- resolve underlying symbols at run time
- use symbol name direclty in wrapper

Fix for Issue 229 negative stdio timers

See merge request !15

Previously, modules would explicitly disable instrumentation when
ever Darshan core called into the module to shut it down. The
issue is that Darshan core starts shutting down well before modules
do, so there is a time interval where modules could be trying to
instrument data while its not safe to do so.

Now, we expose a function (darshan_core_disabled_instrumentation)
that modules can call to determine if its safe to instrument
data.

one counter had spaces instead of underscores

See merge request !14

only tested on Edison so far, and works fine

fix --with-bzlib=DIR ignoring DIR

See merge request !13

editing to clarify this regression testing is for BG systems
@ ALCF, since the scripts assume Cobalt scheduler

added support for DARSHAN_EXCLUDE_DIRS

See merge request !12