Added gui stub with Qt
Added utils to demo
Added directories header to demo
Disabled warning -Wuninitialized reported in Qt
Set query category
Display query image
Set query type
Loading vocabulary in gui
FIXME inline function
Added serialization save() and load() functions to index
Loading index in gui
Added template serialization functions load() and save()
Moved and renamed enum IndexType to DescriptorsType
Moved callbacks to their own compilation unit
FIXME use static instead of inline, fixup with all other similar and move before callback
Added Descriptor class
Renamed test case for descriptors
Added serialization test for Descriptors
Fixed generic header vis.hpp
Refactoring gui utils