widget: Rename API

For consistency, name this vte_terminal_match_remove_all.
all: Rename VteBuffer to VteByteArray

... because I want to use "VteBuffer" for something else.

Conflicts:
	src/iso2022.c
widget: Don't make is_word_char public

Conflicts:
	doc/reference/vte-sections.txt
	src/vte-private.h
	src/vte.c