Remove unused std::time.

[Bo Peng]

Can I apply the attached patch? scons/msvc complains about no
std::time, and std::time is not used in this file.

What is this std::time anyway? A function?

Bo

Index: src/DepTable.cpp
===================================================================
--- src/DepTable.cpp    (revision 19698)
+++ src/DepTable.cpp    (working copy)
@@ -25,9 +25,6 @@

 #include <fstream>

-#ifndef CXX_GLOBAL_CSTD
-using std::time;
-#endif
 using std::endl;
 using std::flush;
 using std::getline;