cross-compiling with BeOS target works.
- tweaked build-procedure to allow for proper generation of a i586-pc-beos
cross-compiler on LINUX.
- added documentation for creation of cross-compiler.
git-svn-id: file:///srv/svn/repos/haiku/trunk/buildtools@11255 a95241bf-73f2-0310-859d-f6bbb57e9c96