Fix many missing std:: which Compaq's cxx wants to have, mostly for two reasons:...

Fix many missing std:: which Compaq's cxx wants to have, mostly for two reasons: 1. because it does not inject the math functions sqrt, sin, cos, fabs, ... into global namespace when we write include<cmath>. 2. because cxx can't do Koenig lookup of functions.

git-svn-id: https://svn.dealii.org/trunk@4795 0785d39b-7218-0410-832d-ea1e28bc413d