BBCode: check for closing tag

[ehku]

Hello,

It's a good thing to still support BBCode in IPS 4 (not a need to my site but I think it's useful to many others), but it's even better to support only correct BBCodes  , i.e. those having an opening and a closing tag.

In the current version, if I type for example

Abc w[i] xyz.

then it will be displayed as

Abc w xyz. 

And all the text after the [] tag are converted to italic. (Like this one, right? No preview button here so I cannot be sure 100%. This is yet another example to show you that the editor is not fully WYSIWYG)

By the way, is there a way to disable BBCode completely? We are a science community and this problem is annoying because people very often write x[ i ] to denote the i-th element of a vector x.

Thank you.