contrib/hgsh/Makefile

zsh_completion: make use of `debuglabelcomplete` command

Use `debuglabelcomplete` command when populating labels list, instead of
calling `hg` three times: for branches, bookmarks and tags. Do not pass string
being completed to `hg debuglabelcomplete` (as `$words[$CURRENT]`), since it
breaks `_hg_revrange` completion (`--rev 2.5:2.5.<Tab>`) for no apparent
benefit.
Also complete `hg view` with labels, not just tags, and drop unused `_hg_tags`.

CC := gcc
CFLAGS := -g -O2 -Wall -Werror

prefix ?= /usr/bin

hgsh: hgsh.o
	$(CC) -o $@ $<

install: hgsh
	install -m755 hgsh $(prefix)

clean:
	rm -f *.o hgsh