add find.1, sed.1, time.1 stubs

all tools should have man pages. add stubs so make install and
make sbase-box-install doesn't fail.

find.1

@@ -0,0 +1,6 @@
+.Dd February 28, 2015
+.Dt FIND 1
+.Os sbase
+.Sh NAME
+.Nm find
+.Nd TODO

sed.1

@@ -0,0 +1,6 @@
+.Dd February 28, 2015
+.Dt SED 1
+.Os sbase
+.Sh NAME
+.Nm sed
+.Nd TODO

time.1

@@ -0,0 +1,6 @@
+.Dd February 28, 2015
+.Dt TIME 1
+.Os sbase
+.Sh NAME
+.Nm time
+.Nd TODO