* runtime_sigprof.cpp: Using real time instead of profile time.
Merge branch '4_9-plugin' into 4_9-plugin-realtime
* runtime_sigprof.cpp: Always update current time(not thread time) on first entry of __start_entry.

Conflicts:
	runtime_sigprof.cpp
Merge branch '4_9-plugin' into 4_9-plugin-realtime
* README.md: Add goals, FAQ, etc.
* runtime_sigprof.cpp (freqency): 100 is also okay.
(MAX_STACK): Rename to max_stack. And disconnected with freqency.
(other functions): Rename MAX_STACK.
Merge branch '4_9-plugin' into 4_9-plugin-realtime
* README.md: Update from 4_9-plugin.
Merge branch '4_9-plugin' into 4_9-plugin-realtime
* README.md: Updated.
Merge branch 'master' into 4_9-plugin-realtime
* license.txt: Add LGPL license.
Conflicts:
	README.md
* runtime_sigprof.cpp: Add GetTimesFromClock decl before UpdateCurrentTime.
* runtime_sigprof.cpp: Change back to SIGPROF, for SIGALRM only effect current thread.
Merge branch '4_9-plugin-realtime' into 4_9-plugin

* runtime_sigprof.cpp: Merge back from 4_9-plugin-realtime. And
deprecate this 4_9-plugin-realtime branch. We always update times
system call.