Remove the sections about replacing libjpeg at run time and compile time. These...

Remove the sections about replacing libjpeg at run time and compile time.  These were written before O/S distributions started shipping libjpeg-turbo, and they are either pedantic or no longer relevant.  Also remove any text that assumes the use of our official project binaries.  Notes specific to the official binaries have been moved into the project wiki.

git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1210 632fc199-4ca6-4c93-a231-07263d6284db