Fluid Layout

Adding proper inheritance to expand functionality from FlowLayout class
to FluidLayout class. The added functionality allows the layout to
properly report its size to parent layouts.
Moved flow layout to gui subfolder
Updated documentation

Updated documentation in HeaderFrame and Kryvos classes.
Updated documentation.

Updated documentation in Crypto, ControlButtonFrame, and Delegate
classes.
Improve DesktopMainWindow

Improve constructor and destructor in DesktopMainWindow class.
Improve FileListFrame

Fix header (it isn't even displayed) and switch types to auto where
appropriate.