Log Message:
Update to 0.10.  Changes in this version:

     o   The bt_logic module was added.  It parses each call to the compiler
         and linker, sorts arguments, adapts them to the current platform and
         runs the resulting converted command.  It also provides generation of
         dependancy files and installation of stuff.

     o   Initial support of shared libraries through bt_logic's framework.
         Buildtool can now build them on different platforms and use different
         naming schemes (needed for Darwin), set rpaths automatically, and
         more.  Note that this is still very experimental.

     o   New tunable features related with libraries are available for Build-
         tool-ized packages.  They are called SHARED and STATIC, and tune
         which kind of libraries you want to build.

     o   Standalone bt_mkdep and bt_install modules were removed.  All their
         functionality is now superseded by bt_logic.

     o   The x11.subr module was added to bt_config.  It provides checks for
         automatic detection of the X Window System.

     o   The pkgconfig.subr module was added to bt_config.  It provides a
         frontend to the pkg-config(1) program.  The bt_check_pkgflags() func-
         tion has been deprecated in favour of this module.

     o   Added functions to automate the detection of a C/C++ compilation en-
         vironment in bt_config.  They are called bt_check_env_c() and
         bt_check_env_cxx().