[Simple-support] invalid attribute name

[<mic...@is...>]

Hello,
I have following issue:

i.e.:
    @Attribute(name = "A+B")
    int a_plus_b = 0;

Simple generates a document on serialization however it is not able to 
deserialize it.
IMO '+' in attribute name violates XML specification.

Shouldn't be attributes names restricted somehow (during writing  to XML 
?) in order to ensure that Simple doesn't generate invalid attribute 
names and therefore incorrect xml document ?

Thanks
Michal