Add support for arbitrary character trimming

[kymckay]

When merged this pull request will:

• Add support for arbitrary character trimming
• This will also fix the functions for strings with non-ASCII characters where the toArray length is different from the length of the original string

Tested and working perfectly (tried with non-ASCII too)

[PabstMirror]

Was failing these tests:

_str = ["   "] call CBA_fnc_leftTrim;
TEST_OP(_str,==,"",_fn);
_str = ["   "] call CBA_fnc_rightTrim;
TEST_OP(_str,==,"",_fn);
_str = [" 	"] call CBA_fnc_rightTrim; // including tabs
TEST_OP(_str,==,"",_fn);

I think this will fix: fa245be