GCC 4.4 support

[shindo]

With recent changes, the project fails to compile with GCC 4.4 (Ubuntu Lucid and CentOS 6).
The problem is __attribute__((deprecated(<message>))), as it's supported starting from GCC 4.5 only.

So, the question is, should we support such an old version of the compiler?

[bioothod]

Drop it.
Adding compiler version support into cmake might be a good idea

[shindo]

Yeah, it may be added to the description/documentation as well.