Added support for quasimatrix expansion in subsref. 
Added support for quasimatrix expansion in subsref. 

For example

>> f = [-1 chebfun(x)]; 
>> f(:)
ans = 
   chebfun column (2 smooth pieces)
       interval       length   endpoint values   
[      -1,       1]        1       -1       -1   
[       1,       3]        2       -1        1   
Total length = 3   vertical scale =   1 



chebfun/chebfun_v4,nickhale/chebfunV4