Class for character array

Class for easier string manipulation, with many operators and functions overloads.

Create a new type called STR with a character array inside, implemented as a structure. It was inspired in Visual Basic syntax.
It was implemented several operators and functions overloads, but allows any character array function using "char" conversor function or ' transpose overload.
It's necessary to create a folder from a MatLab folder in one of the MatLab paths. The folder name is class name, with @ prefix. The .m name is class name.

Operator Overload: ==,~=,<=,>=,>,< -,*,/,\,', [], +,-, (), |
Function Overload: disp, length, upper, lower, strfind
Other Functions: str, left, right, mid, padl,padr, padc, instr, repeat, replace, trim, ltrim, rtrim

Example
=======
s1=str('play');
s1-'l'+ ' t' + 'cricket' - 'cr'
ans=
pay ticket

More details in the start of str.m file and before each function.