Support sampling duration, sampling TIDs (#142)

- Sampling duration config values
  - OMNITRACE_SAMPLING_DURATION
  - OMNITRACE_PROCESS_SAMPLING_DURATION
  - Disables sampling after this time (in seconds) has elapsed 
- Sampling thread-id config values
  - OMNITRACE_SAMPLING_TIDS
  - OMNITRACE_SAMPLING_CPUTIME_TIDS
  - OMNITRACE_SAMPLING_REALTIME_TIDS
  - Allows user to select certain threads for sampling
- Miscellaneous
  - Tweaked the finalization verbosity messages
  - moved sampling-on-child-threads into runtime.hpp and runtime.cpp
  - fixed submodule dyninst header install

source/lib/common/defines.h.in

@@ -97,7 +97,7 @@
 #define OMNITRACE_STRINGIZE(X)           OMNITRACE_STRINGIZE2(X)
 #define OMNITRACE_STRINGIZE2(X)          #X
 #define OMNITRACE_VAR_NAME_COMBINE(X, Y) X##Y
-#define OMNITRACE_VARIABLE(Y)            OMNITRACE_VAR_NAME_COMBINE(_omni_var_, Y)
+#define OMNITRACE_VARIABLE(X, Y)         OMNITRACE_VAR_NAME_COMBINE(X, Y)
 #define OMNITRACE_LINESTR                OMNITRACE_STRINGIZE(__LINE__)
 #define OMNITRACE_ESC(...)               __VA_ARGS__