Stop using exit in parser.

Using exit(EXIT_FAILURE) in the middle of a function makes kgt hard to
be embedded as a library, because it interrupts the caller.

The previous patch removed usage of exit for every generators:
katef#40

This one removes usage of exit for every parser. The parsing_error
struct is introduced to list all the errors.

Issue:
- katef#38
- ArthurSonzogni/Diagon#19

src/Makefile

@@ -4,6 +4,7 @@ SRC += src/ast.c
 SRC += src/ast_binary.c
 SRC += src/bitmap.c
 SRC += src/main.c
+SRC += src/parsing_error.c
 SRC += src/rewrite_ci.c
 SRC += src/rewrite_invisible.c
 SRC += src/txt.c
@@ -22,6 +23,7 @@ ${BUILD}/bin/kgt: ${BUILD}/src/ast.o
 ${BUILD}/bin/kgt: ${BUILD}/src/ast_binary.o
 ${BUILD}/bin/kgt: ${BUILD}/src/bitmap.o
 ${BUILD}/bin/kgt: ${BUILD}/src/main.o
+${BUILD}/bin/kgt: ${BUILD}/src/parsing_error.o
 ${BUILD}/bin/kgt: ${BUILD}/src/rewrite_ci.o
 ${BUILD}/bin/kgt: ${BUILD}/src/rewrite_invisible.o
 ${BUILD}/bin/kgt: ${BUILD}/src/txt.o

src/abnf/io.h

@@ -8,7 +8,7 @@
 #define KGT_ABNF_IO_H
 
 #include "../compiler_specific.h"
-
+#include "../parsing_error.h"
 struct ast_rule;
 
 /*
@@ -17,7 +17,7 @@ struct ast_rule;
  */
 
 struct ast_rule *
-abnf_input(int (*f)(void *opaque), void *opaque);
+abnf_input(int (*f)(void *opaque), void *opaque, parsing_error_queue* errors);
 
 WARN_UNUSED_RESULT
 int