Add include for pause()

main_x11.cpp: In function ‘int main(int, char**)’:
main_x11.cpp:34:15: error: ‘pause’ was not declared in this scope
Add generated src/tester to gitignore
Merge pull request #41 from phihag/fix-add-tester-to-gitignore

Add generated src/tester to gitignore
Merge pull request #42 from phihag/fix-include-for-pause

Add include for pause()
Extra comment on unistd.h include