Update HW1/student/Makefile

Remove redundant lines
Compile main.cpp with OpenCV headers

Before I made this change, compilation with make failed with the
bellow included error. I do not claim THIS is the way how it should
be fixed, but I want to tell you there is a problem and that this
fix works for me. Thanks for your consideration.

…
g++ -c main.cpp -O3 -Wall -Wextra -I /usr/local/cuda/include
In file included from main.cpp:28:
HW2.cpp:1:33: error: opencv2/core/core.hpp: No such file or directory
HW2.cpp:2:39: error: opencv2/highgui/highgui.hpp: No such file or directory
HW2.cpp:3:30: error: opencv2/opencv.hpp: No such file or directory
In file included from main.cpp:28:
HW2.cpp:9: error: ‘cv’ has not been declared
HW2.cpp:9: error: expected constructor, destructor, or type conversion before ‘imageInputRGBA’
HW2.cpp:10: error: ‘cv’ has not been declared
…
Merge remote-tracking branch 'upstream/master'
Should use include-path instead of lib-path
adding large images for students to test and experiment
adding code for timing atomic functions
adding HW#4 files to the repo
adding student_func.cu
fixed minor error in main
adding slides to unit #3 and unit #4
added Johannes' existing CMake files
removed accidental addition of build files
Fixed several of project's CMakeLists.  Fixed one incorrect print string.
added missing CMakelists and hw4 cpp fix from last commit
tweaked compiler arguments to make code compatible with more graphics cards.
removed a debugging line and added myself to credits. =)
moved -Wextra compiler option (specific to GCC) to a UNIX-only section. VS2008 was barfing on it.
simplified several unnecessary inclusions/linkages
Removed unnecessary (but benign) CUDA executable specifiers for compare functions in HW3 and 4
adding device query code