Newlines (\n) can be escaped outside of quoted areas and the newline
will be treated as whitespace but not as an actual line break. Escaping
newlines inside a quoted area is not necessary, and because quotes
trigger literal interpretation of the contents, the escaping backslash
will be parsed as a literal backslash, and the newline will not be
escaped.
Caveat: When a newline is escaped, tokens after it until an unescaped
newline will appear to the parser be on the same line as the initial
token after the last unescaped newline. This may technically lead to
some false line numbers if errors are given, but escaped newlines are
counted so that the next token after an unescaped newline is correct.
See #2766
Before this change, only response headers could be manipulated with the
Caddyfile's 'header' directive.
Also handle the request Host header specially, since the Go standard
library treats it separately from the other header fields...
Use piles from which to draw config values.
Module values can return their name, so now we can do two-way mapping
from value to name and name to value; whereas before we could only map
name to value. This was problematic with the Caddyfile adapter since
it receives values and needs to know the name to put in the config.
Along with several other changes, such as renaming caddyhttp.ServerRoute
to caddyhttp.Route, exporting some types that were not exported before,
and tweaking the caddytls TLS values to be more consistent.
Notably, we also now disable automatic cert management for names which
already have a cert (manually) loaded into the cache. These names no
longer need to be specified in the "skip_certificates" field of the
automatic HTTPS config, because they will be skipped automatically.
