2.28.1: various upgrade issues
1- To make life easier on Xach, stop requiring asdf.lisp to be loaded as source before it's compiled. Instead, wrap each and every single form in an eval-when, most of the time via the with-upgradability macro that also transforms defun into defun* and defgeneric into defgeneric*. Causes massive reindentation :-( 2- Have a proper :version for fallback systems. Will make systems that check the version happier. 3- protect a condition with #+sb-eval. Fixes lp#1116408. 4- Protect warnings-file methods with dynamic when *warnings-file-type* rather than static #+.