pandamonia/A2DynamicDelegate — pull request #3 by deadfalkon (2012-03-16 10:19:49+00:00)
Title: fixed the check for the existance of symbols

The A2BlockDelegate crashed on iOS Versions lower than 4.3 where
``` imp_implementationWithBlock
```
and
```property_copyAttributeValue
```
where not defined.

the existing check
```if (&property_copyAttributeValue)
```
was still resolving the symbol, which wasn´t yet defined and therefore it was useless