fix aspect ratio when resize
out images rect
check if the window system has any OpenGL support
fix hide/show box
fixed timer and stop/start
change menu
Syntax error fixed: #include <QPushbutton> -> #include <QPushButton>
Issue #66 fix : Selection rectangle non-modal
Merge pull request #95 from slima4/master

fix Issue #89
Merge pull request #96 from mbg033/master

#Issue 66 (non-modal selection rectangle) + syntax error fixed in layerwidget.cpp
Merge pull request #97 from m-garanin/master

sync