add extempore-logger minor mode

merge updates to extempore.el from the dsp-refactor branch

add the beginnings of the extempore-logger minor mode

extempore-logging is feature-complete, but doesn't work yet

a couple of extempore-logger bugfixes

make extempore-logger minor mode global

the keystrokes are captured, but the advising isn't working yet

more tweaks to extempore logger, but advices still don't work

fixed advising problem (needed to activate the advice)

also better handling of mixed type arguments

fixed bug in append-to-file call

improved extempore-logging

add regexp to strip out the \r\n chars during logging