add warning flag -W and -pedantic
fix warning ignored-qualifiers with Agent

remove ignored-const in
- Agent class
- Behavior class
- SpyBehavior class
fix warning ignored-qualifiers with Thread

remove ignored-const in
- Thread class
- UtilTime class
fix warning ignored-qualifiers with Sensor & Environment

remove ignored-const in
- Sensor class
- Threadedsensor class
- MockSensor class
- Environment class
add warning flags

-Wcast-qual -Wcast-align -Wwrite-strings
-Wconversion -Wfloat-equal -Wpointer-arith
fix warning conversion with UtilTime
fix to build with clang in Travis CI
fix warning with -Wconversion in Agent & Environment
fix warning with -Wextra-semi

With
- Sensor class
- SensorController class
fix warning with -Wshadow in Thread & SpyBehavior
fix warning with -Wnewline-eof
fix to extract warning as error
Merge pull request #18 from cad-san/fix-build-fail-with-clang

fix build failure with clang