* file_server: Make tests work on Windows
* caddyfile: Fix escaping when character is not escapable
We only escape certain characters depending on inside or outside of
quotes (mainly newlines and quotes). We don't want everyone to have to
escape Windows file paths like C:\\Windows\\... but we can't drop the
\ either if it's just C:\Windows\...
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
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.