Incorrect identification of decimal point as concatenation operator

Coder already had code to handle false warnings of invalid string concatenation for decimal points, however it wasn't handling these two cases: $a = (.01); or $a = (1.) - i.e. where there is opening parentheses following by a dot, or a dot followed by a closing parentheses . The attached patch fixes this. However I think it's a bad practise to use of these, especially the latter. I would prefer 0.01 and 1.0 (or just 1). Perhaps we should add a check for this? I don't know if Drupal has such a coding standard.

Cheers,
Stella

Committed.