like the absence of an input filename. (This simplifies all the
clients codes.) Fixed the dune file for the preprocessor. Fixed
the build of PreprocMain.exe and PreprocMain.byte. Restricted
preprocessing errors [Preproc.Newline_in_string] and
[Preproc.Open_string] to the argument of the #include
directive (instead of general strings: this is for the LIGO lexer
to report the error). I removed the error [Preproc.Open_comment]
as this is for the LIGO lexer to report. The preprocessor scanner
[Preproc.lex] does not take a parameter [is_file:bool] now: the
source file (if any) is determined from the lexing
buffer. Accordingly, the field [is_file] of the state of the
preprocessing lexer has been removed: the lexing buffer becomes
now the reference for the input source (bug fix and interface
improvement). Fixed the comments of the test contract
pledge.religo. I removed the data constructor [Lexer.Stdin], as
redundant with [Lexer.Channel].
Preprocessor is now a library installed by opam.
Replaced ligolang@gmail.com by contact@ligolang.org in opam files.
Reformatted some opam files.
Removed #line directive from preprocessor.
Added to the interface of ParserUnit.
Script messages.sh now checks the identity of .msg and .msg.old
to avoid undue warning about possibly different LR items.
