Use '..' for range instead of '...'

Swift is using .. for (opened) range and ... for closed range. While we're
not convinced of the wisdom of introducing such an typo prone syntax by
supporting both, we see no reason to use a different syntax for (opened)
ranges. Many languages already use '..'. As long as there was no
language using '...' it was fine to be different; not anymore.
Change syntax 'method' to 'met'

We like conciseness.
bootstrap:inference: clarify call inference error message
bootstrap:cprinter: make mkdyn function naming consistent
bootstrap: Switch to uppercase first-letter for export

The naming convention remains lowercase words separated by underscore.
But for exported symbols, the first letter is uppercase.

So it's Html_output; Html_document and Write_html_document; Tcp_window;
String and To_string; Float and round_even_float; etc.

We've gone back and forth on this before, but we resolutely like that it
becomes explicit, at the use-site, whether the symbol is public or
private.
bootstrap: Space rule for unary / binary operator differentiation

If space before and not after: unary. If space before and after, or if
no space before and no space after: binary.
bootstrap: support for unary post op '?' and 'else' binary op
bootstrap: type the intf portion of a fun/met member name declaration

Initially, we intended to make mandatory to always declare the intf of
origin for implemented members, i.e.

	struct a =
		isa `Show

	a met `Show.Show buf:@!`String_buffer = void

To make this possible, we now type the '`Show' portion of the name, for
the benefit of step_check_exhaustive_intf_impl(). That check is still
missing though.

However, we're going to abandon the systematic requirement for
specifying the intf. It quickly becomes painful and is not that helpful
(unlike in languages with inheritance, with an 'override' directive,
these method declarations are not replacing/hiding an existing
behavior).

Instead, the intent is to require such specification when implementing
several members from multiple interfaces that have the same name. This
is not yet supported either.
Remove unnecessary intf path for implemented members

Following the decision in the previous commit, we remove the paths that
have become unnecessary.
Renaming standard module from nlang to n
1/3: bootstrap:lexer: require tabs for indentation
2/3: Switch to TAB indent from 2-space indent in the code
3/3: Accept test outputs
Universally adopt style of \t before types in field declarations
bootstrap: support for new newline escape rules

We may still change them to allow struct literals to span multiple lines
without escaping.
bootstrap: make ' = Void' optional for functions and methods