[Serusers] Radiusclient NG library 0.5.1 and 0.4.9 has been released

[Maxim Sobolev]

Folks,

Due to popular demand I've just made a new releases 0.5.1 and 0.4.9
of Radiusclient NG library, both of them include latest fixes to
make proper validation of incoming Radius replies.

Also I've created RELENG_0_4 branch just in the case we will need
to make some more fixes to 0.4.x series.

Therefore please make sure you are using the latest version before
reporting any bugs.

-Maxim