Cleaning up some command line parsing where on some OS's quotes are stripped by the OS and on some they are not. This fixes a failing Boost Build configuration.py unit test on Cygwin.

[SVN r48502]

tools/build

@@ -1 +1 @@
-Subproject commit 5d8c130d7e8d8ef2d902a8aa00eb67bf390e7b3a
+Subproject commit 8dd8f437c6ca88a06f1ad444883730fb7ce4d633