document tex sampler bug fix, code changes

docs/relnotes-7.0.html

@@ -34,11 +34,14 @@ TBD
 <li>Fixed an R300 driver bug that caused Xorg composite manager to crash
 <li>Fixed R300 vertex program/matrix bug (10848)
 <li>GLSL dFdx() and dFdy() work for fragment program inputs now (texcoords)
+<li>Specifying an invalid texture unit as a sampler could lead to a crash
 </ul>
 
 
 <h2>Internal code changes</h2>
 <ul>
+<li>Some texture code consolidation and simplifiction (Ian Romanick)
+<li>R300 driver clean-ups.
 </ul>