Merge from origin/emacs-25

Merge from origin/emacs-25

8c2946e In NEWS describe new handling of window margins (Bug#24193)
0cee66c Facultatively ignore margins when splitting and resizing wind...
8d68147 Document CATEGORY arg to modify-category-entry
8342e74 Document char-script-table's effect on word motion
e9ff485 Further fix for 'url-http-create-request' and multibyte strings
0695235 Fix docstring of eval-expression
98b01dd Clarify when 'cursor' property is in effect
75f1882 Convert the remaining strings to unibyte before concatenating
d2db5dd Fix bug with handling the bidi cache
ccd0e92 * doc/lispref/text.texi (Change Hooks): Minor copyedits.
f785ff4 Clarify documentation of before/after-change-functions
3c9cb57 Document use of vectors in keymaps

# Conflicts:
#	src/xdisp.c