better edgepoint d-to-h transfer

[griwodz]

transfer points from lower resolution first
limit number of edge points transferred device-to-host

[fabiencastan]

I have tested this PR, but I still have an error:

terminate called after throwing an instance of 'std::logic_error'
  what():  EdgePointCollection::add_point: too many edge points

Backtrace:

#0  0x0000003095635877 in raise () from /lib64/libc.so.6
#1  0x0000003095636f68 in abort () from /lib64/libc.so.6
#2  0x00007fffea0e511d in __gnu_cxx::__verbose_terminate_handler () at ../../.././libstdc++-v3/libsupc++/vterminate.cc:95
#3  0x00007fffea0e3176 in __cxxabiv1::__terminate (handler=<optimized out>) at ../../.././libstdc++-v3/libsupc++/eh_terminate.cc:47
#4  0x00007fffea0e31c1 in std::terminate () at ../../.././libstdc++-v3/libsupc++/eh_terminate.cc:57
#5  0x00007fffea0e33d9 in __cxxabiv1::__cxa_throw (obj=0x95b2d60, tinfo=0x7fffea3735b0 <typeinfo for std::logic_error>,	dest=0x7fffea0f7a50 <std::logic_error::~logic_error()>) at ../../.././
libstdc++-v3/libsupc++/eh_throw.cc:87
#6  0x00007ffff680cfd5 in cctag::EdgePointCollection::add_point(int, int, float, float) () from /s/apps/packages/mikrosVfx/multiview/cctag/dev_mikros/platform-linux/build-debug/lib/libCCTag.
so.1.0.0
#7  0x00007ffff67d23d4 in cctag::edgesPointsFromCanny(cctag::EdgePointCollection&, cv::Mat const&, cv::Mat const&, cv::Mat const&) () from /s/apps/packages/mikrosVfx/multiview/cctag/dev_mikr
os/platform-linux/build-debug/lib/libCCTag.so.1.0.0
#8  0x00007ffff6807f0f in cctag::cctagMultiresDetection(boost::ptr_list<cctag::CCTag, boost::heap_clone_allocator, std::allocator<void*> >&, cv::Mat const&, cctag::ImagePyramid const&, unsig
ned long, cctag::TagPipe*, cctag::Parameters const&, cctag::logtime::Mgmt*) () from /s/apps/packages/mikrosVfx/multiview/cctag/dev_mikros/platform-linux/build-debug/lib/libCCTag.so.1.0.0
#9  0x00007ffff67d6d30 in cctag::cctagDetection(boost::ptr_list<cctag::CCTag, boost::heap_clone_allocator, std::allocator<void*> >&, int, unsigned long, cv::Mat const&, cctag::Parameters con
st&, cctag::CCTagMarkersBank const&, bool, cctag::logtime::Mgmt*) () from /s/apps/packages/mikrosVfx/multiview/cctag/dev_mikros/platform-linux/build-debug/lib/libCCTag.so.1.0.0
#10 0x00007ffff67fa842 in cctag::cctagDetection(boost::ptr_list<cctag::ICCTag, boost::heap_clone_allocator, std::allocator<void*> >&, int, unsigned long, cv::Mat const&, cctag::Parameters co
nst&, cctag::logtime::Mgmt*, cctag::CCTagMarkersBank const*) () from /s/apps/packages/mikrosVfx/multiview/cctag/dev_mikros/platform-linux/build-debug/lib/libCCTag.so.1.0.0
#11 0x0000000000afa4a1 in openMVG::features::CCTAG_Image_describer::Describe (this=0x13834c8, image=..., regions=..., mask=0x0) at /s/apps/packages/mikrosVfx/multiview/openMVG/popart_develop
/repo/src/openMVG/features/cctag/CCTAG_describer.cpp:93
#12 0x0000000000af6e51 in openMVG::features::SIFT_CCTAG_Image_describer::Describe (this=0x1383480, image=..., regions=..., mask=0x0) at /s/apps/packages/mikrosVfx/multiview/openMVG/popart_de
velop/repo/src/openMVG/features/cctag/SIFT_CCTAG_describer.cpp:42
#13 0x00000000009e0a71 in <lambda()>::operator()(void) const (__closure=0x7fffffff5c40) at /s/apps/packages/mikrosVfx/multiview/openMVG/popart_develop/repo/src/software/SfM/main_ComputeFeatu
res.cpp:530
#14 0x00000000009e28e4 in main (argc=1,	argv=0x7fffffff6798) at /s/apps/packages/mikrosVfx/multiview/openMVG/popart_develop/repo/src/software/SfM/main_ComputeFeatures.cpp:536