* Add android support for tengine
* modify tengine download use commit id
* Del some invalid log in Tengine
* Test. default enable tengine
* ndk version judegment
* Close test . set Tengine default OFF
* Logic problem
* test .Android NDK judgement .
* Cmake error modify.
* cmake: cleanup tengine scripts
* cmake: use tengine target name
* cmake: disable testing of BUILD_ANDROID_PROJECTS=OFF
* Close test .
* Add Tengine support .
* Modify printf to CV_LOG_WARNING
* a few minor fixes in the code
* Renew Tengine version
* Add header file for CV_LOG_WARNING
* Add #ifdef HAVE_TENGINE in tengine_graph_convolution.cpp
* remove trailing whitespace
* Remove trailing whitespace
* Modify for compile problem
* Modify some code style error
* remove whitespace
* Move some code style problem
* test
* add ios limit and build problem
* Modified as alalek suggested
* Add cmake 2.8 support
* modify cmake 3.5.1 problem
* test and set BUILD_ANDROID_PROJECTS OFF
* remove some compile error
* remove some extra code in tengine
* close test.
* Test again
* disable android.
* delete ndk version judgement
* Remove setenv() call . and add License information
* Set tengine default OFF. Close test .
Co-authored-by: Vadim Pisarevsky <vadim.pisarevsky@gmail.com>
