Add dependencies options and -fcopybook-deps

cobc:
* pplex.l (cb_text_list): prevent duplicates
* cobc.c, help.c, pplex.l: add new flags to output dependencies following gcc: -M to output deps only, -MD to output deps while compiling (in .d files), -MP to output phony targets, -MG to keep missing copybooks, -MQ <target> to Makefile-quote target ; add -fcopybook-deps to output only copybook names instead of file paths. -fcopybook-deps also forces -E, -foneline-deps, -MT=copybooks, disables errors on missing copybooks and removes output on stdout
doc:
* gnucobol.texi: document new dependencies options

NEWS

@@ -65,6 +65,9 @@ NEWS - user visible changes				-*- outline -*-
 ** New option -fdefault-file-colseq to specify the default
    file collating sequence
 
+** New options -M, -MP, -MG, -MD and -MQ to output COPY dependencies
+   to a file (see "Dependencies options" in the GnuCOBOL manual)
+
 * More notable changes
 
 ** execution times were significantly reduced for the following:

cobc/ChangeLog

@@ -24,6 +24,10 @@
 	* typeck.c (cb_emit_accept): always check position
 	* cobc.c, flag.def: make scope optional for -fdump
 
+2024-09-23  David Declerck <[email protected]>
+
+	* pplex.l (cb_text_list): prevent duplicates
+
 2024-08-28  David Declerck <[email protected]>
 
 	* tree.c (char_to_precedence_idx, get_char_type_description, valid_char_order):
@@ -139,6 +143,16 @@
 	* codegen.c: handle profiling code generation under the
 	  cb_flag_prof guard
 
+2024-03-15  Fabrice Le Fessant <[email protected]>
+
+	* cobc.c, help.c, pplex.l: add new flags to output dependencies following
+	  gcc: -M to output deps only, -MD to output deps while compiling (in
+	  .d files), -MP to output phony targets, -MG to keep missing copybooks,
+	  -MQ <target> to Makefile-quote target ; add -fcopybook-deps to
+	  output only copybook names instead of file paths. -fcopybook-deps
+	  also forces -E, -foneline-deps, -MT=copybooks, disables errors on
+	  missing copybooks and removes output on stdout
+
 2024-02-19  Boris Eng <[email protected]>
 
 	* parser.y (screen_value_clause): replaced basic literals by literals