Fix path.glob relative path

doc/Jamfile.v2

@@ -1,12 +1,15 @@
 # Copyright David Abrahams 2006. Distributed under the Boost
 # Software License, Version 1.0. (See accompanying
 # file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-import docutils ;
 
+import docutils ;
 import path ;
-sources = [ path.glob . : *.rst ] ;
+
+path-constant HERE : . ;
+
+sources = [ path.glob $(HERE) : *.rst ] ;
 bases = $(sources:S=) ;
-  
+
 # This is a path relative to the html/ subdirectory where the
 # generated output will eventually be moved.
 stylesheet = "--stylesheet=rst.css" ;