remove varables in MAT file(s)

removevar removes variable(s) from selected Mat file(s)
removevar selects MAT file(s) matfiles and ask user to select which
variables to delete. If more than one MAT file, matfiles is of cell format. Otherwise, matfiles can be either of char or cell class.
removevar(matfiles) ask user to select which variables in matfiles to delete removevar(matfiles,varargin) deletes variables that matches varargin in matfiles.

Usage Examples:
removevar
removevar('temp.mat','abc','img')
removevar({'temp1.mat','temp2.mat'},'abc','img')