Fix the problem that frame rate becomes slower than the specified value.
install_dependencies debian & ubuntu, gtk3 package was wrong
Merge branch 'master' of github.com:openframeworks/openFrameworks
kiss_fft.h: reaklines
ofTrueTypeFont: initialize all members in constructor
Merge pull request #2993 from nistetsurooy/more-precise-fps

Fix the problem that frame rate becomes slower than the specified value.
ofSetFramerate: more explanative variable names and comments + CHANGELOG
fix last ocmmit
linux: more precise timming function through monotonic clock