include compat.h before everything else

fix counter in scroll-line-up

fix redraw when side window is visible

jump to line in the current buffer!

add other-window (C-x o) and allow focusing help buffer

recompute help only when needed

move in_minibuffer too

always include compat.h first

move some initializations to minibuffer.c

reorder minibuffer stuff and while there also rename the bogus completing_read to minibuffer_read. To get a ``completing-read'' one has to call enter_minibuffer with the right parameters.

move help to its own file in order to do so, we also have to export some internal variables from ui (the width and height of the window). Not the best possible outcome, but are used only in recompute_help, and can be dropped later. Also, move wrap_page to wrap.c.

misc doc improvements

explain how to customise about: pages

allow about: pages to be locally overridden

refactoring tab-close and tab-close-other: introduce free_tab