common: Replace std::regex with RE2C state machines.

To avoid GCC 4.9 dependency.

Fixes #370.
diff --git a/common/trace_parser.hpp b/common/trace_parser.hpp
index 0dfaabe..fb24743 100644
--- a/common/trace_parser.hpp
+++ b/common/trace_parser.hpp
@@ -138,9 +138,11 @@
     EnumSig *parse_enum_sig();
     BitmaskSig *parse_bitmask_sig();
     
+public:
     static CallFlags
     lookupCallFlags(const char *name);
 
+protected:
     Call *parse_Call(Mode mode);
 
     void parse_enter(Mode mode);