fix the mismatch of perf_test, add a performance sample for ocl module
Simplify the bind texture logic of interpolate frame function
remove the device specific logic
Add option --with-score to summary.py to automatically classify speedups

Legend for new column is:
* FASTER - strong speedup
* faster - spedup is detected but it is unreliable
* <empty> - no change in speed
* slower - slowdown is detected but it is unreliable
* SLOWER - strong slowdown
Put the cl_image support detection in utils
pyrlk also take advantages of cl_image support detection
fix the compile warnings
Merge pull request #553 from bitwangyaoyao:2.4_perfTest
Merge pull request #554 from bitwangyaoyao:2.4_impvInterFrame
Merge pull request #556 from bitwangyaoyao:2.4_SURF
Merge pull request #563 from taka-no-me:perf_classify_speedups