Fixes for fitting windows and frames to their buffers (Bug#37563)

Fixes for fitting windows and frames to their buffers (Bug#37563)

* lisp/window.el (window-default-font-height)
(window-default-line-height): New functions.
(fit-frame-to-buffer): Interpret values of MAX-HEIGHT and
MIN-HEIGHT arguments in terms of WINDOW's default line height
(Bug#37563).
(fit-window-to-buffer): Obey size restricting arguments even
when size of WINDOW's text does not change.  Do not
temporarily select WINDOW and perform height/width related
calculations if and only if WINDOW is accordingly combined.
Interpret values of MAX-HEIGHT and MIN-HEIGHT arguments in
terms of WINDOW's default line height.