Set up fontification independent of font-lock.

Basic functionality in place.  need to test further and expand detail fortification.
fontifying xact starts and postings.

initial testing looks better than previous font-lock methods.  Need run time and performance testing.
Merge branch 'master' into new-fontification-scheme
Not working well, try something else on new-fontification-scheme-2
no message
Merge branch 'master' into new-fontification-scheme
not much progress here.
improved xact iteration so fontify-whole-buffer doesn't miss xact separated by more than a single empty line
meh.  Still chugging along.
Merge branch 'master' into new-fontification-scheme
jit-lock is now calling ledger-fontify-buffer-part, but font-lock-fontify-region is still being called and fighting with it.
Solved the fight between jit-lock.  But for some reason it isn't calling it for all regions in the buffer.
Seems to be working.  I wasn't ensuring I caught all the xacts in a region specified by hit lock.
Now I need to prune code
New fortification is working.

Code pruned.
Merge branch 'new-fontification-scheme'