title: What does %=% mean in Android.mk for OpenCV4Android?
body: <p>In Android.mk for OpenCVAndroid, there are lines as below:</p>
  
  <pre><code>MY_PREFIX := $(LOCAL_PATH)
  MY_SOURCES := $(wildcard $(MY_PREFIX)/*.cpp)
  LOCAL_SRC_FILES := $(MY_SOURCES:$(MY_PREFIX)%=%)
  </code></pre>
  
  <p>What does %=% mean?
  I refer to the manual of GNU make, but fail to find the answer.
  What are final local source files ('LOCAL_SRC_FILES')?</p>