[phobos] phobos commit, revision 2157

[dsource.org]

phobos commit, revision 2157


user: Don Clugston

msg:
D implementation of pow(), avoiding dependence on C. The big benefit is that pow() is now pure, but also improved accuracy of corner cases. 
All math functions are now @safe or @trusted, and all are pure nothrow except where implemented by C functions.

http://www.dsource.org/projects/phobos/changeset/2157