--Creates a tabbed window with an existing figure moved into each tab.
--No tab workarounds necessary - MATLAB's built-in but undocumented tab
features are used for smooth graphics handling and a clean interface.

Input parameters:
figHandles: an array of handles to currently valid, visible figures.
These figures can be GUIDE based.

Output parameters:
(optional): The handle to the tabbed figure is output if desired.

Example:
f1 = figure('Name','Sin Wave');
plot(sin(1:100));
f2 = figure('Name','Random Points');
plot(magic(5))
f3 = msgbox('A message box');
tabbedFig = figs2tabs([f1,f2,f3])

Warning:
This code heavily relies on undocumented Matlab functionality.
It has only been tested on Matlab 2012a. Use at your own risk.

Known limitations:
--uimenu's are not preserved
--figure-wide callback functions are not preserved, i.e. KeyPressFcn,
CloseRequestFcn.
--resizing is not proportional (this will be fixed in a future release)

Known issues:
*Not compatible with pre r2010b versions of Matlab, though it could be with
some slight modifications to this function. Compatibility fixes
are welcome from those with older versions.