Patched boost-base.jam to allow rules in stage target requirements

Fixed grammar in build_system.htm
Added vc7.1-tools.jam/.html for msvc 7.1
Updated the regex lib Jamfile to build correctly-named libraries


[SVN r18319]

libs/regex

@@ -1 +1 @@
-Subproject commit 0ed72c37e4f8bb95f648ab2016d3493889363af6
+Subproject commit 640f63339505ce8231585dbde5cdfca520af6812

tools/build

@@ -1 +1 @@
-Subproject commit 69e76f312f3cdae68a2f358fb8867ec6f5c2097e
+Subproject commit 098bd7ebb174b739edc059cc3fbbbf1ff418fb65