diff: replace --merge option by config option
I can't think of any reason you'd want to enable the merge diff on a
run-to-run basis; you'd probably either always or never want it set
(though I can't see why you'd never want it set). If you have it set,
you'll probably also want the same output in `hg log -p`
output. Having a single config option for the feature makes sense.
Differential Revision: https://phab.mercurial-scm.org/D9956
# See http://EditorConfig.org for the specification
root = true
[*.py]
indent_size = 4
indent_style = space
trim_trailing_whitespace = true
end_of_line = lf
[*.{c,h}]
indent_size = 8
indent_style = tab
trim_trailing_whitespace = true
end_of_line = lf
[*.t]
indent_size = 2
indent_style = space
trim_trailing_whitespace = false
end_of_line = lf