introducting new zipped Pencil File Format

this change introduces new zipped Pencil File Format,
in "pencil.pro" file added "fileformat.h" to the list of HEADERS and "fileformat.cpp" to the list of SOURCES, added QUAZIP and ZLIB libs to Linux version
in "src/interface/editor.cpp" modified openObject() method to open only new file format
in "src/interface/mainwindow2.cpp" modified saveObject() method to save only new file format
added "fileformat.h" and "fileformat.cpp" files with some preprocessor defines and one function needed by new file format
in files "src/structure/layerbitmap.cpp", "src/structure/layersound.cpp", "src/structure/layervector.cpp" modified folder name, where corresponding layer-files are stored.