hgmerge: add cleanup functions
This patch adds functions cleanup, success and failure.
The last two of these should be used instead of exit.
Current code was changed to use them.
It also moves $HGTMP to the top of the file (it's used in the cleanup
function), changes the comment and removes now unneeded trap
in the diff+patch merge.
include hg
recursive-include mercurial *.py
include hgweb.cgi hgwebdir.cgi
include hgeditor rewrite-log
include tests/README tests/run-tests tests/test-*[a-z0-9] tests/*.out
prune tests/*.err
include *.txt
include templates/map templates/map-*[a-z0-9]
include templates/*.tmpl
include doc/README doc/Makefile doc/*.txt doc/*.html doc/*.[0-9]
recursive-include contrib *
include README
include CONTRIBUTORS
include COPYING
include Makefile
include MANIFEST.in