Add another note about unpacking and changing directories

Thread starts here: http://linuxfromscratch.org/pipermail/lfs-support/2007-December/033870.html

I really don't think that any additional reminder is necessary, especially since the note about unpacking is a mere 2 pages before the first package. I also have a feeling that adding such a reminder to, say, the Binutils installation page, would cause people reading it to think it only applies to Binutils. There are a couple of other possibilities though...

1. The "Introduction" page, with that info, could be swapped with the "Toolchain Technical Notes" page. I suppose that the bit about unpacking and cd'ing to the source dir might be forgotten in all the technical details (most of which, as is even stated on that page, aren't even necessary for a successful LFS build anyway). Also, am I the only one that thinks the "Toolchain Technical Notes" could simply be moved to an Appendix, considering that anyone who isn't already an expert in building from source probably won't understand most of that until after building a system anyway?

2. The text about unpacking the source and entering the directory could be slightly differently worded. For example, the part about using the lfs user applies only to Chapter 5, and the part about the bash shell is just plain redundant (or at the very least, in the wrong place...if anything that would be more appropriate in the "Host System Reqs."). Perhaps the bit about the lfs user could be moved to the beginning of the Chapter 5 introduction page (something like "The lfs user should be used throughout this chapter, until stated otherwise").

Added a General Compilation Instructions section immediatley before binutils. Essentially reordered the presentation that was in the Chapter 5 Introduction.

Fixed in revision 8704.