.editorconfig

fileset: add "tracked()" to explicitly select files in the revision

I'm going to rewrite filesets to be match predicates, which means basic
patterns such as '*' will no longer be "closed" to the subset constructed
from the ctx.

Good thing is that 'hg status "set:not binary()"' can include unknown files
out of the box, and fileset computation will likely to be faster as we won't
have to walk dirstate twice, for example. Bad thing is that we can't select
files at a certain revision by 'set:revs(REV, **)' since '**' is "open" to
any paths. So, this patch introduces "tracked()" as a replacement for the '**'
in the example above.

# See http://EditorConfig.org for the specification

root = true

[*.py]
indent_size = 4
indent_style = space
trim_trailing_whitespace = true

[*.{c,h}]
indent_size = 8
indent_style = tab
trim_trailing_whitespace = true

[*.t]
indent_size = 2
indent_style = space
trim_trailing_whitespace = false