Fixes as suggested by @nickhale.

This works both on 2014a and 2014b on my machine (Mac).
Making CHEBGUI work in 2014b as well as previous versions.

This might cause some conflicts with the IVP branch, however,
I'm sure those can be dealt with when the time comes.
Removing 2014b warning.
Reinstating the logo in chebgui.

For some reason, MATLAB keeps making it disappear when changes
are made to the GUI.
Merge branches 'hotfix-2014-chebgui' and 'hotfix-2014b-chebsnake'